The <taxon tax_id="562">Escherichia coli</taxon> protein mrp is a 41 kDa ATP-binding protein of unknown function. Homologs are present in other bacteria including <taxon tax_id="1423">Bacillus subtilis</taxon> ybaL, <taxon tax_id="727">Haemophilus influenzae</taxon> HI1277, <taxon tax_id="1148">Synechocystis sp.</taxon> (strain PCC 6803) slr0067; and also in eukaryotes, for example human NBP, yeast NBP35 and YIL003w, <taxon tax_id="6239">Caenorhabditis elegans</taxon> F10G8.6; and in archaebacteria, for example <taxon tax_id="2190">Methanocaldococcus jannaschii</taxon> (Methanococcus jannaschii) MJ0283.