Upon overexpression inhibits growth. Binds to 70S and 100S ribosomes, probably via the 30S subunit. Predominantly localized to 1 cell pole in stationary phase, with a few smaller foci elsewhere in the cell; polar localization depends on the minCDE operon. Maximally expressed after 2 days growth, i.e. during stationary phase (at protein level). Expression is regulated by RpoS. Not essential (in strain K12 / BW25113). Belongs to the ElaB/YgaM/YqjD family.