Mitochondrial Translational Release Factor 1 (MTRF1)

MTRF1 was determined by in silico methods to be a mitochondrial protein with similarity to the peptide chain release factors (RFs) discovered in bacteria and yeast. Initially thought to have a role in the termination of mitochondria protein synthesis, a recent publication found no mitochondrial translation release functionality. Multiple alternatively spliced transcript variants have been suggested by mRNA and EST data; however, their full-length natures are not clear.The deduced 445-amino acid MTRF1 protein lacks a clear N-terminal mitochondrial targeting signal but has the signature sequences expected for class I release factors. Human MTRF1 shares 40% amino acid sequence identity with E. coli RF1, 32% identity with S. cerevisiae RF1, and 30% identity with C. elegans RF1.