Protein Family Models

ParB is a component of the par system which mediates accurate DNA partition during cell division. It recognises A-box and B-box DNA motifs. ParB forms an asymmetric dimer with 2 extended helix-turn-helix (HTH) motifs that bind to A-boxes. The HTH motifs emanate from a beta sheet coiled coil DNA binding module [1]. Both DNA binding elements are free to rotate around a flexible linker, this enables them to bind to complex arrays of A- and B-box elements on adjacent DNA arms of the looped partition site [1]. [1]. 16306995. Structures of ParB bound to DNA reveal mechanism of partition. complex formation.. Schumacher MA, Funnell BE;. Nature. 2005;438:516-519. (from Pfam)

Date:

2024-08-14

This HMM represents the most well-conserved core of a set of chromosomal and plasmid partition proteins related to ParB, including Spo0J, RepB, and SopB. Spo0J has been shown to bind a specific DNA sequence that, when introduced into a plasmid, can serve as partition site. Study of RepB, which has nicking-closing activity, suggests that it forms a transient protein-DNA covalent intermediate during the strand transfer reaction.

Date:

2021-04-27