Component of the mitochondrial large ribosomal subunit (mt-LSU) (PubMed:25278503, PubMed:25838379, PubMed:28892042). Mature mammalian 55S mitochondrial ribosomes consist of a small (28S) and a large (39S) subunit. The 28S small subunit contains a 12S ribosomal RNA (12S mt-rRNA) and 30 different proteins. The 39S large subunit contains a 16S rRNA (16S mt-rRNA), a copy of mitochondrial valine transfer RNA (mt-tRNA(Val)), which plays an integral structural role, and 52 different proteins (PubMed:25278503, PubMed:25838379). Interacts with OXA1L (By similarity). Belongs to the universal ribosomal protein uL13 family.