The Escherichia coli protein mrp is a 41 Kd ATP-binding protein of unknown function. Homologs are present in other bacteria (for example: Bacillus subtilis ybaL, Hemophilus influenzae HI1277, Synechocystis PCC 6803 slr0067) as well as in eukaryotes (human NBP, yeast NBP35 and YIL003w, Caenorhabditis elegans F10G8.6) and in archaebacteria (Methanococcus jannaschii MJ0283).

We developed a signature pattern for this family based on a conserved region located about 100 residues after the ATP/GTP-binding motif 'A' (P-loop) (see <PDOC00017>).