DNA helicase subunit AddA (IPR014152)

Short name: DNA_helicase_suAddA

Overlapping homologous superfamilies

Family relationships


AddAB, also called RexAB, substitutes for RecBCD in several bacterial lineages. These DNA recombination proteins act before synapse and are particularly important for DNA repair of double-stranded breaks by homologous recombination. The term AddAB is used broadly, with AddA homologues between the Firmicutes and the alphaproteobacteria, while the partner AddB proteins show no strong homology across the two groups of species.

The AddA/AddB heterodimer acts as both an ATP-dependent DNA helicase and an ATP-dependent, dual-direction single-stranded exonuclease. It recognises the chi site generating a DNA molecule suitable for the initiation of homologous recombination. The AddA nuclease domain is required for chi fragment generation; this subunit has the helicase and 3' -> 5' nuclease activities

GO terms

Biological Process

GO:0006302 double-strand break repair

Molecular Function

GO:0004003 ATP-dependent DNA helicase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.