Giardia duodenalis has two recombinases (GdDMC1A & GdDMC1B), both bear characteristic recombinase domains: DNA binding, ATPcap, Walker A/B.

Purified rGdDMC1B carries out: ssDNA and dsDNA binding, ATP hydrolysis, and DNA strand exchange.

Gamma radiation causes double strand breaks (DSB) in DNA from trophozoites as demonstrated by increased phosphorylated levels of histone GdH2A.

DSB induce an increase on dmc1B transcript and protein suggesting its participation in DSB repair and its protein is found in the nuclei.

With all these findings, we are proposing that GdDMC1B has a Rad51 functional role during DNA damage repair.