ATPase that binds to both the 70S ribosome and the 50S ribosomal subunit in a nucleotide-independent manner. Weakly expressed during exponential growth in rich medium, stops at onset of stationary phase. In minimal medium is more strongly expressed and continues into stationary phase, part of the ychF-rpsF-ssbA-rpsR operon (PubMed:14762004). No visible phenotype. Belongs to the TRAFAC class OBG-HflX-like GTPase superfamily. OBG GTPase family. YchF/OLA1 subfamily.