Question

What are the eukaryotic counterparts for RecBCD?

Answer 1

Answer-

MRX protein complex (Mre11, Rad50 and Xrs2) is eukaryotic counterparts for RecBCD protein complex.

Double strand break in DNA is a serious threat to cell survival. It arises quite frequently. If these breaks are not being repaired, the fate of the cell will be very disastrous. The major mechanism used to repair double strand break in most cells is homologous recombination. In E. coli, it is done by RecBCD complex. RecBCD is composed of three subunits (recB, recC and recD). It has both helicase and nuclease activity.

In eukaryotes MRX complex is responsible for this repair mechanism. MRX protein is responsible for the resection of the 5'- ending strands at the break site. Dmc1 and Rad51 proteins then assemble on the single stranded tail.