This protein family is found in many different bacterial species but is of viral origin. The protein forms an oligomer and functions as a processive alkaline exonuclease that digests linear double-stranded DNA in a Mg(2+)-dependent reaction, It has a preference for 5'-phosphorylated DNA ends. It thus forms part of the two-component SynExo viral recombinase functional unit [1].

1: Bacteriophage SPP1 Chu is an alkaline exonuclease in the SynExo family of viral two-component recombinases. Vellani TS, Myers RS; J Bacteriol. 2003;185:2465-2474. PMID:12670970