Protein Family Models

WHH is a predicted nuclease of the HNH/ENDO VII superfamily of the treble clef fold. The name is derived from the conserved motif WHH. It is found in bacterial polymorphic toxin systems [1] and functions as a toxin module. WHH is the shortest version of HNH nuclease families. Like AHH and LHH, the WHH nuclease contains 4 conserved histidines of which the first one is predicted to bind a metal-ion and other three ones are involved in activation of water molecule for hydrolysis [1]. [1]. 21306995. A novel immunity system for bacterial nucleic acid degrading. toxins and its recruitment in various eukaryotic and DNA viral. systems.. Zhang D, Iyer LM, Aravind L;. Nucleic Acids Res. 2011;39:4532-4552. (from Pfam)

Date:

2024-08-14

Colicin-like bacteriocins are complex structures with an N-terminal beta-barrel translocation domain (Pfam:PF09000), a long double-alpha-helical receptor-binding domain (Pfam:PF11570) and this C-terminal RNAse/DNase domain with endonuclease activity. Their competitor bacteriocidal action is by a process that involves binding to a surface receptor, entering the cell, and, finally, killing it. The lethal action of colicin E3 is a specific cleavage in the ribosomal decoding A site. The crystal structure of colicin E3 reveals a Y-shaped molecule with the receptor binding domain forming a 100 Angstrom long stalk and the two globular heads of the translocation domain and this catalytic domain comprising the two arms [2]. [1]. 10368275. The crystal structure of the DNase domain of colicin E7 in. complex with its inhibitor Im7 protein.. Ko TP, Liao CC, Ku WY, Chak KF, Yuan HS;. Structure. 1999;7:91-102.. [2]. 11741540. Crystal structure of colicin E3: implications for cell entry and. ribosome inactivation.. Soelaiman S, Jakes K, Wu N, Li C, Shoham M;. Mol Cell. 2001;8:1053-1062. (from Pfam)

Date:

2024-08-14