The protein encoded by this gene is a GTPase that localizes to the mitochondrion. The encoded protein binds to the 3' terminal stem loop of 12S mitochondrial rRNA and is required for proper assembly of the 28S small mitochondrial ribosomal subunit. Deletion of this gene has been shown to cause mitochondrial dysfunction, growth retardation, and apoptosis. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2015].