Transfer RNA gene arrangement and codon usage in vertebrate mitochondrial genomes: a new insight into gene order conservation.

Background: Mitochondrial (mt) gene arrangement has been highly conserved among vertebrates from jawless fishes to mammals for more than 500 million years. It remains unclear, however, whether such long-term persistence is a consequence of some constraints on the gene order.

Results: Based on the analysis of codon usage and tRNA gene positions, we suggest that tRNA gene order of the typical vertebrate mt-genomes may be important for their translational efficiency.