What is "mt-tg"

Mitochondrially encoded tRNA glycine also known as MT-TG is a transfer RNA which in humans is encoded by the mitochondrial MT-TG gene.

MT-TG is a small 68 nucleotide RNA (human mitochondrial map position 9991-10058) that transfers the amino acid glycine to a growing polypeptide chain at the ribosome site of protein synthesis during translation.