The human mitochondrial ribosomal protein genes: Mapping of 54 genes to the chromosomes and implications for human disorders

Mitochondria possess their own translational machinery, which is composed o f components distinct from their cytoplasmic counterparts. To investigate t he possible involvement of mitochondrial ribosomal defects in human disease , we mapped nuclear genes that encode mitochondrial ribosomal proteins (MRP s). We generated sequence-tagged sites (STSs) of individual MRP genes that were able to be detected by PCR. They were placed on an STS content map of the human genome by typing of radiation hybrid panels. We located 54 MRP ge nes on the STS-content map and assigned these genes to cytogenetic bands of the human chromosomes. Although mitochondria are thought to have originate d from bacteria, in which the genes encoding ribosomal proteins are cluster ed into operons, the mapped MRP genes are widely dispersed throughout the g enome, suggesting that transfer of each MRP gene to the nuclear genome occu rred individually. We compared the assigned positions with candidate region s for mendelian disorders and found certain genes that might be involved in particular diseases. This map provides a basis for studying possible roles of MRP defects in mitochondrial disorders.