Bacteriophage SPO1-encoded TF1 binds and bends DNA
This group contains proteins related to bacillus phage SPO1-encoded transcription factor 1 (TF1), a type II DNA-binding protein related to the DNA sequence specific (IHF) and non-specific (HU) domains. Type II DNA-binding proteins bind and bend DNA as dimers. Like IHF, TF1 binds DNA specifically and bends DNA sharply. Bacteriophage SPO1-encoded TF1 recognizes SPO1 phage DNA containing 5-(hydroxymethyl)-2'-deoxyuridine as opposed to thymine, Related family members includes integration host factor (IHF) and HU, also called type II DNA-binding proteins (DNABII), which are small dimeric proteins that specifically bind the DNA minor groove, inducing large bends in the DNA and serving as architectural factors in a variety of cellular processes such as recombination, initiation of replication/transcription and gene regulation. IHF binds DNA in a sequence specific manner while HU displays little or no sequence preference. IHF homologs are usually heterodimers, while HU homologs are typically homodimers (except HU heterodimers from E. coli and other enterobacteria). HU is highly basic and contributes to chromosomal compaction and maintenance of negative supercoiling, thus often referred to as histone-like protein. IHF is an essential cofactor in phage lambda site-specific recombination, having an architectural role during assembly of specialized nucleoprotein structures (snups).
Jiyao W et al.(2023). "The conserved domain database in 2023.",