The protein encoded by this gene is a peptidyl-tRNA hydrolase and a vital component of the large mitochondrial ribosome. The encoded protein serves as a ribosome release factor for this ribosome, which translates mitochondrial genes. This protein may be responsible for degrading prematurely-terminated polypeptides and for reusing stalled ribosomes. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2014].