The members of this family are are all hypothetical bacterial proteins of unknown function, and are similar to the YbbR protein expressed by Bacillus subtilis (Swiss:O34659, Swiss:O87088). One member (Swiss:Q97EN2) is annotated as an uncharacterized secreted protein, whereas another member (Swiss:P43521) is described as a hypothetical protein in the 5'region of the def gene of Thermus thermophilus, which encodes a deformylase [1], but no further information was found in either case. This region is found repeated up to four times in many members of this family.

1: Characterization of the Thermus thermophilus locus encoding peptide deformylase and methionyl-tRNA(fMet) formyltransferase. Meinnel T, Blanquet S; J Bacteriol 1994;176:7387-7390. PMID:7961514