The function of OSGEPL1 (O-sialoglycoprotein endopeptidase like 1, Ensembl gene identifier ENSG00000128694) is as follows. Required for the formation of a threonylcarbamoyl group on adenosine at position 37 (t(6)A37) in mitochondrial tRNAs that read codons beginning with adenine. Probably involved in the transfer of the threonylcarbamoyl moiety of threonylcarbamoyl-AMP (TC-AMP) to the N6 group of A37. Involved in mitochondrial genome maintenance. {ECO:0000255|HAMAP-Rule:MF_03179, ECO:0000269|PubMed:29760464, ECO:0000269|PubMed:32047918}.