phosphoacceptor receiver (REC) domain of response regulators (RRs) and pseudo response regulators (PRRs); Two-component systems (TCSs) involving a sensor and a response regulator are used by bacteria to adapt to changing environments. Processes regulated by two-component systems in bacteria include sporulation, pathogenicity, virulence, chemotaxis, and membrane transport. Response regulators (RRs) share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. Response regulators regulate transcription, post-transcription or post-translation, or have functions such as methylesterases, adenylate or diguanylate cyclase, c-di-GMP-specific phosphodiesterases, histidine kinases, serine/threonine protein kinases, and protein phosphatases, depending on their output domains. The function of some output domains are still unknown. TCSs are found in all three domains of life - bacteria, archaea, and eukaryotes, however, the presence and abundance of particular RRs vary between the lineages. Archaea encode very few RRs with DNA-binding output domains; most are stand-alone REC domains. Among eukaryotes, TCSs are found primarily in protozoa, fungi, algae, and green plants. REC domains function as phosphorylation-mediated switches within RRs, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFtpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:cd17580    48 SDIGMPGMDGYELARRLREL--PWLANTPAIALTGYGQPEDRERALEAGFDAHLVKPVDPDELIELI 112

second phosphoacceptor receiver (REC) domain of Dictyostelium discoideum hybrid signal transduction histidine kinase D and similar domains; Dictyostelium discoideum hybrid signal transduction histidine kinase D (DhkD) is a large protein that contains two histidine kinase (HK) and two REC domains on the intracellular side of a single pass transmembrane domain, and extracellular PAS and PAC domains that likely are involved in ligand binding. This model represents the second REC domain and similar domains. DhkD activates the cAMP phosphodiesterase RegA to ensure proper prestalk and prespore patterning, tip formation, and the vertical elongation of the mound into a finger, in Dictyostelium discoideum. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFtpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:cd17580    48 SDIGMPGMDGYELARRLREL--PWLANTPAIALTGYGQPEDRERALEAGFDAHLVKPVDPDELIELI 112

Response regulator receiver domain; This domain receives the signal from the sensor partner in bacterial two-component systems. It is usually found N-terminal to a DNA binding effector domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:pfam00072  49 DINMPGMDGLELLKRIRRRDP----TTPVIILTAHGDEDDAVEALEAGADDFLSKPFDPDELLAAI 110

second phosphoacceptor receiver (REC) domain of Dictyostelium discoideum hybrid signal transduction histidine kinase D and similar domains; Dictyostelium discoideum hybrid signal transduction histidine kinase D (DhkD) is a large protein that contains two histidine kinase (HK) and two REC domains on the intracellular side of a single pass transmembrane domain, and extracellular PAS and PAC domains that likely are involved in ligand binding. This model represents the second REC domain and similar domains. DhkD activates the cAMP phosphodiesterase RegA to ensure proper prestalk and prespore patterning, tip formation, and the vertical elongation of the mound into a finger, in Dictyostelium discoideum. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFtpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:cd17580    48 SDIGMPGMDGYELARRLREL--PWLANTPAIALTGYGQPEDRERALEAGFDAHLVKPVDPDELIELI 112

phosphoacceptor receiver (REC) domain of hybrid sensor histidine kinases/response regulators similar to Arabidopsis thaliana CKI1 and Escherichia coli RcsC; This family is composed of hybrid sensor histidine kinases/response regulators that are sensor histidine kinases (HKs) fused with a REC domain, similar to the sensor histidine kinase CKI1 from Arabidopsis thaliana, which is involved in multi-step phosphorelay (MSP) signaling that mediates responses to a variety of important stimuli in plants. MSP involves a signal being transferred from HKs via histidine phosphotransfer proteins (AHP1-AHP5) to nuclear response regulators. The CKI1 REC domain specifically interacts with the downstream signaling protein AHP2, AHP3 and AHP5. The plant MSP system has evolved from the prokaryotic two-component system (TCS), which allows organisms to sense and respond to changes in environmental conditions. This family also includes bacterial hybrid sensor HKs such as Escherichia coli RcsC, which is a component of the Rcs signalling pathway that controls a variety of physiological functions like capsule synthesis, cell division, and motility. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFtPEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:cd17546    49 DLQMPVMDGLEATRRIREL-EGGGRRTPIIALTANALEEDREKCLEAGMDDYLSKPVKLDQLKEVL 113

DNA-binding response regulator, OmpR family, contains REC and winged-helix (wHTH) domain [Signal transduction mechanisms, Transcription];

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2566851310   4 DISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLV 73
Cdd:COG0745    52 DLMLPGMDGLEVCRRLR----ARPSDIPIIMLTARDDEEDRVRGLEAGADDYLTKPFDPEELLARIRALL 117

Response regulator c-di-GMP phosphodiesterase, RpfG family, contains REC and HD-GYP domains [Signal transduction mechanisms];

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFtpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLVA 74
Cdd:COG3437    56 LDVRMPGMDGFELLRLLRAD--PSTRDIPVIFLTALADPEDRERALEAGADDYLTKPFDPEELLARVRNALE 125

Response regulator receiver domain; This domain receives the signal from the sensor partner in bacterial two-component systems. It is usually found N-terminal to a DNA binding effector domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:pfam00072  49 DINMPGMDGLELLKRIRRRDP----TTPVIILTAHGDEDDAVEALEAGADDFLSKPFDPDELLAAI 110

DNA-binding response regulator DpiB of citrate/malate metabolism [Transcription, Signal transduction mechanisms];

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2566851310   4 DISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLVA 74
Cdd:COG4565    56 DIYLPDGDGLELLRELR----ARGPDVDVIVITAARDPETVREALRAGVVDYLIKPFTFERLREALERYLE 122

phosphoacceptor receiver (REC) domain of NarL (Nitrate/Nitrite response regulator L) family response regulators; The NarL family is one of the more abundant families of DNA-binding response regulators (RRs). Members of the NarL family contain a REC domain and a helix-turn-helix (HTH) DNA-binding output domain, with a majority of members containing a LuxR-type HTH domain. They function as transcriptional regulators. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAIlRLVA 74
Cdd:cd17535    51 DLSMPGMDGIEALRRLRRRYP----DLKVIVLTAHDDPEYVLRALKAGAAGYLLKDSSPEELIEAI-RAVA 116

two component system sensor kinase;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:PRK15347  741 DIRMPGLDGLETTQLWRDDPNNLDPDCMIVALTANAAPEEIHRCKKAGMNHYLTKPVTLAQLARAL 806

phosphoacceptor receiver (REC) domain of YesN and related helix-turn-helix containing response regulators; This family is composed of uncharacterized response regulators that contain a REC domain and a AraC family helix-turn-helix (HTH) DNA-binding output domain, including Bacillus subtilis uncharacterized transcriptional regulatory protein YesN and Staphylococcus aureus uncharacterized response regulatory protein SAR0214. YesN is a member of the two-component regulatory system YesM/YesN and SAR0214 is a member of the probable two-component regulatory system SAR0215/SAR0214. Also included in this family is the AlgR-like group of LytTR/AlgR family response, which includes Pseudomonas aeruginosa positive alginate biosynthesis regulatory protein AlgR and Bacillus subtilis sensory transduction protein LytT, among others. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFTPEaggnIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLVA 74
Cdd:cd17536    51 TDIRMPGMDGLELIEKIRELYPD----IKIIILSGYDDFEYAQKAIRLGVVDYLLKPVDEEELEEALEKAKE 118

phosphoacceptor receiver (REC) domain of DNA-binding transcriptional regulator NtrC; DNA-binding transcriptional regulator NtrC is also called nitrogen regulation protein NR(I) or nitrogen regulator I (NRI). It contains an N-terminal receiver (REC) domain, followed by a sigma-54 interaction domain, and a C-terminal helix-turn-helix DNA-binding domain. It is part of the two-component regulatory system NtrB/NtrC, which controls expression of the nitrogen-regulated (ntr) genes in response to nitrogen limitation. DNA-binding response regulator NtrC is phosphorylated by NtrB; phosphorylation of the N-terminal REC domain activates the central sigma-54 interaction domain and leads to the transcriptional activation from promoters that require sigma(54)-containing RNA polymerase. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFTPeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILR 71
Cdd:cd19919    50 SDIRMPGMDGLALLAQIKQRHP----DLPVIIMTAHSDLDSAVSAYQGGAFEYLPKPFDIDEAVALVER 114

phosphoacceptor receiver (REC) domain of DrrD-like OmpR family response regulators; DrrD is a OmpR/PhoB homolog from Thermotoga maritima whose function is not yet known. This subfamily also includes Streptococcus agalactiae transcriptional regulatory protein DltR, part of the DltS/DltR two-component system (TCS), and Pseudomonas aeruginosa transcriptional activator protein PfeR, part of the PfeR/PfeS TCS, which activates expression of the ferric enterobactin receptor. The DltS/DltR TCS regulates the expression of the dlt operon, which comprises four genes (dltA, dltB, dltC, and dltD) that catalyze the incorporation of D-alanine residues into the lipoteichoic acids. Members of this subfamily belong to the OmpR/PhoB family, which comprises of two domains, an N-terminal receiver domain and a C-terminal DNA-binding winged helix-turn-helix effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2566851310   4 DISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIA---AILR 71
Cdd:cd17625    48 DIMLPGMDGLEVLKSLR----EEGIETPVLLLTALDAVEDRVKGLDLGADDYLPKPFSLAELLArirALLR 114

phosphoacceptor receiver (REC) domain of uncharacterized hybrid sensor histidine kinase/response regulators; Typically, two-component regulatory systems (TCSs) consist of a sensor (histidine kinase) that responds to specific input(s) by modifying the output of a cognate response regulator (RR). TCSs allow organisms to sense and respond to changes in environmental conditions. Hybrid sensor histidine kinase/response regulators contain all the elements of a classical TCS in a single polypeptide chain. RRs share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2566851310   3 SDISMPDMDGYMLIRQVRTfTPEAgGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRL 72
Cdd:cd17598    48 SDIVMPEMDGYELCRKIKS-DPDL-KDIPVILLTTLSDPRDVIRGLECGADNFITKPYDEKYLLSRIKYI 115

phosphoacceptor receiver (REC) domain of C4-dicarboxylic acid transport protein D (DctD) and similar proteins; C4-dicarboxylic acid transport protein D (DctD) is part of the two-component regulatory system DctB/DctD, which regulates C4-dicarboxylate transport via regulation of expression of the dctPQM operon and dctA. It is an activator of sigma(54)-RNA polymerase holoenzyme that uses the energy released from ATP hydrolysis to stimulate the isomerization of a closed promoter complex to an open complex capable of initiating transcription. DctD is a member of the NtrC family, characterized by a domain architecture containing an N-terminal REC domain, followed by a central sigma-54 interaction/ATPase domain, and a C-terminal DNA binding domain. The ability of the central domain to hydrolyze ATP and thus to interact effectively with a complex of RNA polymerase, sigma54, and promoter, is controlled by the phosphorylation status of the REC domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFTPEaggnIPAIALTAYArdeDQQQAIQAgfqMH------LPKPVDTEKLIAAILR 71
Cdd:cd17549    48 SDIRMPGMDGLELLAQIRELDPD----LPVILITGHG---DVPMAVEA---MRagaydfLEKPFDPERLLDVVRR 112

nitrogen regulation protein NR(I); Provisional

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFTPEaggnIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLVA 74
Cdd:PRK10923   53 SDIRMPGMDGLALLKQIKQRHPM----LPVIIMTAHSDLDAAVSAYQQGAFDYLPKPFDIDEAVALVERAIS 120

phosphoacceptor receiver (REC) domain of probable transcriptional regulator Ycf29; Ycf29 is a probable response regulator of a two-component system (TCS), typically consisting a sensor and a response regulator, that functions in adaptation to changing environments. Processes regulated by TCSs in bacteria include sporulation, pathogenicity, virulence, chemotaxis, and membrane transport. Ycf29 contains an N-terminal REC domain and a LuxR-type helix-turn-helix DNA-binding output domain. REC domains function as phosphorylation-mediated switches within RRs, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFTPEAggNIPAIALTAYARDEDQQQAIQAGFQMHLPKP 59
Cdd:cd19927    48 SDIIMPGVDGYSLLGKLRKNADFD--TIPVIFLTAKGMTSDRIKGYNAGCDGYLSKP 102

phosphoacceptor receiver (REC) domain of PmrA-like OmpR family response regulators; This subfamily contains various OmpR family response regulators including PmrA, BasR, QseB, tctD, and RssB, which are components of two-component regulatory systems (TCSs). The PmrA/PmrB TCS controls transcription of genes that are involved in lipopolysaccharide modification in the outer membrane of bacteria, increasing bacterial resistance to host-derived antimicrobial peptides. The BasS/BasR TCS functions as an iron- and zinc-sensing transcription regulator. The QseB/QseC TCS activates the flagella regulon by activating transcription of FlhDC. The RssA/RssB TCS regulates swarming behavior in Serratia marcescens. OmpR family DNA-binding response regulators contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2566851310   4 DISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIA---AILR 71
Cdd:cd17624    49 DLGLPDGDGLDLLRRWR----RQGQSLPVLILTARDGVDDRVAGLDAGADDYLVKPFALEELLArlrALLR 115

phosphoacceptor receiver (REC) domain of PrrA-like OmpR family response regulators; The Mycobacterium tuberculosis PrrA is part of the PrrA/PrrB two-component system (TCS) that has been implicated in early intracellular multiplication and is essential for viability. Also included in this subfamily is Mycobacterium tuberculosis MprA, part of the MprAB TCS that regulates EspR, a key regulator of the ESX-1 secretion system, and is required for establishment and maintenance of persistent infection in a tissue- and stage-specific fashion. PrrA and MprA belong to the OmpR family of DNA-binding response regulators, which contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2566851310   4 DISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAyaRDE--DQQQAIQAGFQMHLPKPVDTEKLIA---AILR 71
Cdd:cd17627    49 DVMMPRLDGLEVCRRLR----AAGNDLPILVLTA--RDSvsDRVAGLDAGADDYLVKPFALEELLArvrALLR 115

DNA-binding response regulator, LytR/AlgR family [Transcription, Signal transduction mechanisms];

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPeaggNIPAIALTAYarDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLVA 74
Cdd:COG3279    54 DIQMPGLDGFELARQLRELDP----PPPIIFTTAY--DEYALEAFEVNAVDYLLKPIDEERLAKALEKAKE 118

phosphoacceptor receiver (REC) domain of FixJ family response regulators; FixJ family response regulators contain an N-terminal receiver domain (REC) and a C-terminal LuxR family helix-turn-helix (HTH) DNA-binding output domain. The Sinorhizobium meliloti two-component system FixL/FixJ regulates nitrogen fixation in response to oxygen during symbiosis. Under microaerobic conditions, the kinase FixL phosphorylates the response regulator FixJ resulting in the regulation of nitrogen fixation genes such as nifA and fixK. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2566851310   4 DISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILR 71
Cdd:cd17537    51 DVRMPGMSGLELQDELL----ARGSNIPIIFITGHGDVPMAVEAMKAGAVDFLEKPFRDQVLLDAIEQ 114

DNA-binding response regulator, FixJ family, consists of REC and HTH domains [Signal transduction mechanisms, Transcription];

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   4 DISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYArdeDQQ---QAIQAG---FqmhLPKPVDTEKLIAAILRLVA 74
Cdd:COG4566    50 DVRMPGMSGLELQEELA----ARGSPLPVIFLTGHG---DVPmavRAMKAGavdF---LEKPFDDQALLDAVRRALA 116

phosphoacceptor receiver (REC) domain of chemotaxis protein CheV and similar proteins; This subfamily includes the REC domains of Bacillus subtilis chemotaxis protein CheV, Myxococcus xanthus gliding motility regulatory protein FrzE, and similar proteins. CheV is a hybrid protein with an N-terminal CheW-like domain and a C-terminal CheY-like REC domain. The CheV pathway is one of three systems employed by B. subtilis for sensory adaptation that contribute to chemotaxis. It is involved in the transmission of sensory signals from chemoreceptors to flagellar motors. Together with CheW, it is involved in the coupling of methyl-accepting chemoreceptors to the central two-component histidine kinase CheA. FrzE is a hybrid sensor histidine kinase/response regulator that is part of the Frz pathway that controls cell reversal frequency to support directional motility during swarming and fruiting body formation. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTfTPeAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKP 59
Cdd:cd19924    57 TDIEMPKMDGYELTFELRD-DP-RLANIPVILNSSLSGEFSRARGKKVGADAYLAKF 111

phosphoacceptor receiver (REC) domain of KdpE-like OmpR family response regulators; KdpE is a component of the KdpD/KdpE two-component system (TCS) and is activated when histidine kinase KdpD senses a drop in external K+ concentration or upshift in ionic osmolarity, resulting in the expression of a heterooligomeric transporter KdpFABC. In addition, the KdpD/KdpE TCS is also an adaptive regulator involved in the virulence and intracellular survival of pathogenic bacteria. KdpE is a member of the OmpR family of DNA-binding response regulators that contain REC and winged helix-turn-helix (wHTH) DNA-binding output effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310  4 DISMPDMDGYMLIRQVRTFTpeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKP 59
Cdd:cd17620   49 DLGLPDMDGLEVIRRLREWS-----AVPVIVLSARDEESDKIAALDAGADDYLTKP 99

chemotaxis protein CheY;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   3 SDISMPDMDGYMLIRQVRtfTPEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKP 59
Cdd:PRK10610   56 SDWNMPNMDGLELLKTIR--ADGAMSALPVLMVTAEAKKENIIAAAQAGASGYVVKP 110

acid-sensing system histidine kinase EvgS;

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2566851310    3 SDISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKL 65
Cdd:PRK09959  1008 TDVNMPNMDGFELTRKLR----EQNSSLPIWGLTANAQANEREKGLSCGMNLCLFKPLTLDVL 1066

acetoacetate metabolism transcriptional regulator AtoC;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPEAggniPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKL 65
Cdd:PRK11361   55 DIRMPEMDGIKALKEMRSHETRT----PVILMTAYAEVETAVEALRCGAFDYVIKPFDLDEL 112

first (D1) phosphoacceptor receiver (REC) domain of response regulator PleD and similar domains; PleD contains a REC domain (D1) with the phosphorylatable aspartate, a REC-like adaptor domain (D2), and the enzymatic diguanylate cyclase (DGC) domain, also called the GGDEF domain according to a conserved sequence motif, as its output domain. The GGDEF-containing PleD response regulators are global regulators of cell metabolism in some important human pathogens. This model describes D1 of PleD and similar domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   4 DISMPDMDGYMLIRQVRTFtpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPV 60
Cdd:cd17538    50 DVMMPGMDGFEVCRRLKED--PETRHIPVIMITALDDREDRIRGLEAGADDFLSKPI 104

response regulator FixJ; Provisional

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2566851310   3 SDISMPDMDGYMLIRQVRtftpEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLVAT 75
Cdd:PRK09390   53 TDVRMPGIDGIELLRRLK----ARGSPLPVIVMTGHGDVPLAVEAMKLGAVDFIEKPFEDERLIGAIERALAQ 121

phosphoacceptor receiver (REC) domain of PhoB response regulator from the OmpR family; The transcription factor PhoB is a component of the PhoR/PhoB two-component system, a key regulatory protein network that facilitates response to inorganic phosphate (Pi) starvation conditions by turning on the phosphate (pho) regulon whose products are involved in phosphorus uptake and metabolism. PhoB is a member of the OmpR family of DNA-binding response regulators that contains REC and winged helix-turn-helix (wHTH) DNA-binding output effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310   4 DISMPDMDGYMLIRQVRTftPEAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:cd17618    51 DWMLPGGSGIQFIRRLKR--DEMTRDIPIIMLTARGEEEDKVRGLEAGADDYITKPFSPRELVARI 114

phosphoacceptor receiver (REC) domain of BfmR-like OmpR family response regulators; Acinetobacter baumannii BfmR is part of the BfmR/S two-component system that functions as the master regulator of biofilm initiation. BfmR confers resistance to complement-mediated bactericidal activity, independent of capsular polysaccharide, and also increases resistance to the clinically important antimicrobials meropenem and colistin, making it a potential antimicrobial target. Its inhibition would have the dual benefit of significantly decreasing in vivo survival and increasing sensitivity to selected antimicrobials. Members of this subfamily belong to the OmpR family of DNA-binding response regulators, which are characterized by a REC domain and a winged helix-turn-helix (wHTH) DNA-binding output effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTpeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIA---AILR 71
Cdd:cd19939    50 DIMLPGMDGLTVCREVREHS-----HVPILMLTARTEEMDRVLGLEMGADDYLCKPFSPRELLArvrALLR 115

phosphoacceptor receiver (REC) domain of CtrA-like OmpR family response regulators; CtrA is part of the CckA-ChpT-CtrA phosphorelay that is conserved in alphaproteobacteria and is important in orchestrating the cell cycle, polar development, and flagellar biogenesis. CtrA is the master regulator of flagella synthesis genes and also regulates genes involved in the cell cycle, exopolysaccharide synthesis, and cyclic-di-GMP signaling. CtrA is active as a transcription factor when phosphorylated. It is a member of the OmpR family of DNA-binding response regulators, characterized by a REC domain and a winged helix-turn-helix (wHTH) DNA-binding output effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2566851310   4 DISMPDMDGYMLIRQVRTftpeAGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAILRLV 73
Cdd:cd17616    49 DLNLPDMSGYEVLRTLRL----AKVKTPILILSGLADIEDKVKGLGFGADDYMTKPFHKDELVARIHAIV 114

phosphoacceptor receiver (REC) domain of Brucella abortus CpdR and CckA, and similar domains; Two-component systems (TCSs), consisting of a sensor and a response regulator, are used by bacteria to adapt to changing environments. Processes regulated by TCSs in bacteria include sporulation, pathogenicity, virulence, chemotaxis and membrane transport. Response regulators share the common phosphoacceptor REC domain and differ output domains such as DNA, RNA, ligand, and protein-binding, or enzymatic domain. CpdR is a stand-alone REC protein. CckA is a sensor histidine kinase containing N-terminal PAS domains and a C-terminal REC domain. CpdR and CckA are components of a regulatory phosphorelay system (composed of CckA, ChpT, CtrA and CpdR) that controls Brucella abortus cell growth, division, and intracellular survival inside mammalian host cells. CckA autophosphorylates in the presence of ATP and transfers a phosphoryl group to the conserved aspartic acid residue on its C-terminal REC domain, which is relayed to the ChpT phosphotransferase. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFTPeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKP 59
Cdd:cd18160    50 TDIVMPEMDGIELAREARKIDP----DVKILFISGGAAAAPELLSDAVGDNATLKKP 102

aerobic respiration control sensor protein ArcB; Provisional

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPEAggNIPAI-ALTAYARdEDQQQAIQAGFQMHLPKPVDTEKLIAAILRL 72
Cdd:PRK11091  576 DIQLPDMTGLDIARELRERYPRE--DLPPLvALTANVL-KDKKEYLDAGMDDVLSKPLSVPALTAMIKKF 642

phosphoacceptor receiver (REC) domain of PdtaR and similar proteins; This subfamily includes Mycobacterium tuberculosis PdtaR, also called Rv1626, and similar proteins containing a REC domain and an ANTAR (AmiR and NasR transcription antitermination regulators) RNA-binding output domain. PdtaR is a response regulator that acts at the level of transcriptional antitermination and is a member of the PdtaR/PdtaS two-component regulatory system. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPeaggnIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:cd19932    52 DVKMPRLDGIEAAKIITSENI-----APIVLLTAYSQQDLVERAKEAGAMAYLVKPFSESDLIPAI 112

DNA-binding response regulator HprR;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310   4 DISMPDMDGYMLIRQVRTftpeaGGNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKLIAAI 69
Cdd:PRK11517   51 DIMLPGMDGWQILQTLRT-----AKQTPVICLTARDSVDDRVRGLDSGANDYLVKPFSFSELLARV 111

phosphoacceptor receiver (REC) domain of type B Arabidopsis response regulators (ARRs) and similar domains; Type-B ARRs (Arabidopsis response regulators) are a class of MYB-type transcription factors that act as major players in the transcriptional activation of cytokinin-responsive genes. They directly regulate the expression of type-A ARR genes and other downstream target genes. Cytokinin is a plant hormone implicated in many growth and development processes including shoot organogenesis, leaf senescence, sink/source relationships, vascular development, lateral bud release, and photomorphogenic development. Cytokinin signaling involves a phosphorelay cascade by histidine kinase receptors (AHKs), histidine phosphotransfer proteins (AHPs) and downstream ARRs. ARRs are divided into two groups, type-A and -B, according to their sequence and domain structure. Type-B ARRs contain a receiver (REC) domain and a large C-terminal extension that has characteristics of an effector or output domain, with a Myb-like DNA binding domain referred to as the GARP domain. The GARP domain is a motif specific to plant transcription factors. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2566851310   3 SDISMPDMDGYMLIRQVRTFTpeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKPVDTEKL 65
Cdd:cd17584    50 TDVHMPDMDGFEFLELIRLEM-----DLPVIMMSADGSTSTVMKGLAHGACDYLLKPVSIEDL 107

phosphoacceptor receiver (REC) domain of plant ethylene receptors ETR1, ETR2, and EIN4, and similar proteins; Plant ethylene receptors contain N-terminal transmembrane domains that contain an ethylene binding site and also serve in localization of the receptor to the endoplasmic reticulum or the Golgi apparatus and a C-terminal histidine kinase (HK)-like domain. There are five ethylene receptors (ETR1, ERS1, ETR2, ERS2, and EIN4) in Arabidopsis thaliana. ETR1, ETR2, and EIN4 also contain REC domains C-terminal to the HK domain. ETR1 and ERS1 belong to subfamily 1, and have functional HK domains while ETR2, ERS2, and EIN4 belong to subfamily 2, and lack the necessary residues for HK activity and may function as serine/threonine kinases. The plant hormone ethylene plays an important role in plant growth and development. It regulates seed germination, seedling growth, leaf and petal abscission, fruit ripening, organ senescence, and pathogen responses. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPEAGGniPAI-ALTAYARDEDQQQAIQAGFQMHLPKPVDTEKL 65
Cdd:cd19933    53 DLCMPEMDGFEVALRIRKLFGRRER--PLIvALTANTDDSTREKCLSLGMNGVITKPVSLHAL 113

phosphoacceptor receiver (REC) domain of ChvI-like OmpR family response regulators; Sinorhizobium meliloti ChvI is part of the ExoS/ChvI two-component regulatory system (TCS) that is required for nitrogen-fixing symbiosis and exopolysaccharide synthesis. ExoS/ChvI also play important roles in regulating biofilm formation, motility, nutrient utilization, and the viability of free-living bacteria. ChvI belongs to the OmpR family of DNA-binding response regulators that contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 2566851310  4 DISMPDMDGYMLIRQVRTFTpeaggNIPAIALTAYARDEDQQQAIQAGFQMHLPKP 59
Cdd:cd19936   49 DIKMPRMDGMELLQRLRQKS-----TLPVIFLTSKDDEIDEVFGLRMGADDYITKP 99

phosphoacceptor receiver (REC) domain of Thermotoga maritima response regulator TrrA and similar domains; Thermotoga maritima contains a two-component signal transduction system (TCS) composed of the ThkA sensory histidine kinase (HK) and its cognate response regulator (RR) TrrA; the specific function of the system is unknown. TCSs couple environmental stimuli to adaptive responses. TrrA is a stand-alone RR containing only a REC domain with no output/effector domain. The REC domain itself functions as an effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30
                  ....*....|....*....|....*....|....*
gi 2566851310   4 DISMPDMDGYMLIRQVRTFTPeaggNIPAIALTAY 38
Cdd:cd17554    51 DIKMPGMDGLETLRKIREKKP----DLPVIICTAY 81