Alternative titles; symbols
HGNC Approved Gene Symbol: MRPS18B
Cytogenetic location: 6p21.33 Genomic coordinates (GRCh38): 6:30,617,840-30,626,392 (from NCBI)
Mitochondria have their own translation system for production of 13 inner membrane proteins essential for oxidative phosphorylation. MRPS18B is a component of the small subunit of the mitochondrial ribosome that is encoded by the nuclear genome (Koc et al., 2001).
By proteolytic digestion of whole bovine 28S subunits, followed by peptide analysis and EST database analysis, Koc et al. (2001) identified full-length human MRPS18B, which they called MRPS18-2. The deduced MRPS18B protein contains 258 amino acids and has a calculated molecular mass of 29.3 kD. Removal of a predicted 25-amino acid N-terminal mitochondrial localization signal results in a mature 26.5-kD protein. Koc et al. (2001) noted that 1 Mrps18 protein is present in E. coli, whereas other organisms contain several Mrps18 orthologs. Humans have 3 MRPS18 proteins, MRPS18A (611981), MRPS18B, and MRPS18C (611983), that share sequence conservation only in their central regions. Mouse and human MRPS18B share 78.4% amino acid identity.
By genomic sequence analysis, Zhang and Gerstein (2003) mapped the MRPS18B gene to chromosome 6p21.3. They identified MRPS18B pseudogenes on chromosomes 1 and 2.
Koc, E. C., Burkhart, W., Blackburn, K., Moseley, A., Spremulli, L. L. The small subunit of the mammalian mitochondrial ribosome: identification of the full complement of ribosomal proteins present. J. Biol. Chem. 276: 19363-19374, 2001. [PubMed: 11279123] [Full Text: https://doi.org/10.1074/jbc.M100727200]
Zhang, Z., Gerstein, M. Identification and characterization of over 100 mitochondrial ribosomal protein pseudogenes in the human genome. Genomics 81: 468-480, 2003. [PubMed: 12706105] [Full Text: https://doi.org/10.1016/s0888-7543(03)00004-1]