InterPro: IPR000119 Histone-like bacterial DNA-binding protein

Bacteria synthesise a set of small, usually basic proteins of about 90 residues that bind DNA and are known as histone-like proteins [1, 2]. Examples include the HU protein in Escherichia coli is a dimer of closely related alpha and beta chains and in other bacteria can be a dimer of identical chains. HU-type proteins have been found in a variety of eubacteria, cyanobacteria and archaebacteria, and are also encoded in the chloroplast genome of some algae [3]. The integration host factor (IHF), a dimer of closely related chains which seem to function in genetic recombination as well as in translational and transcriptional control [4] is found in enterobacteria and viral proteins include the African Swine fever virus protein A104R (or LMW5-AR) [5].

The exact function of these proteins is not yet clear but they are capable of wrapping DNA and stabilising it from denaturation under extreme environmental conditions. The structure is known for one of these proteins [6]. The protein exists as a dimer and two "beta-arms" function as the non-specific binding site for bacterial DNA.