MRPL58 is an essential component of the mitochondrial large ribosomal subunit that functions as a codon-independent peptidyl-tRNA hydrolase 1. The protein acts as a translation release factor that has lost stop codon specificity and directs translation termination in mitochondria, particularly during abortive elongation events 1. MRPL58 is involved in hydrolyzing peptidyl-tRNAs that have been prematurely terminated, thereby facilitating the recycling of stalled mitochondrial ribosomes 1. The protein contains a conserved GGQ motif that undergoes glutamine methylation by HEMK1, though this modification appears dispensable for normal cellular function under standard culture conditions 2. Structurally, MRPL58 shares functional homology with bacterial ribosome rescue factors like ArfB and ICT1, demonstrating conserved mechanisms for resolving ribosomal stalling across species 3. The protein's rescue activity is specifically effective on ribosomes stalled with limited mRNA extension past the A site, highlighting its specialized role in mitochondrial quality control 3. This ribosome rescue function is essential for maintaining mitochondrial protein synthesis and cellular viability, representing a critical component of mitochondrial translation machinery.