Mamit-tRNA, a database of mammalian mitochondrial tRNA primary and secondary structures

Abstract

Mamit-tRNA (http://mamit-tRNA.u-strasbg.fr), a database for mammalian mitochondrial genomes, has been developed for deciphering structural features of mammalian mitochondrial tRNAs and as a helpful tool in the frame of human diseases linked to point mutations in mitochondrial tRNA genes. To accommodate the rapid growing availability of fully sequenced mammalian mitochondrial genomes, Mamit-tRNA has implemented a relational database, and all annotated tRNA genes have been curated and aligned manually. System administrative tools have been integrated to improve efficiency and to allow real-time update (from GenBank Database at NCBI) of available mammalian mitochondrial genomes. More than 3000 tRNA gene sequences from 150 organisms are classified into 22 families according to the amino acid specificity as defined by the anticodon triplets and organized according to phylogeny. Each sequence is displayed linearly with color codes indicating secondary structural domains and can be converted into a printable two-dimensional (2D) cloverleaf structure. Consensus and typical 2D structures can be extracted for any combination of primary sequences within a given tRNA specificity on the basis of phylogenetic relationships or on the basis of structural peculiarities. Mamit-tRNA further displays static individual 2D structures of human mitochondrial tRNA genes with location of polymorphisms and pathology-related point mutations. The site offers also a table allowing for an easy conversion of human mitochondrial genome nucleotide numbering into conventional tRNA numbering. The database is expected to facilitate exploration of structure/function relationships of mitochondrial tRNAs and to assist clinicians in the frame of pathology-related mutation assignments.

Analysis of complete mitochondrial genomes of patients with schizophrenia and bipolar disorder

“…20 We have identified 10 variants in tRNA genes (Supplementary Table 3), but none of them is likely pathogenic, as they involve nucleotide positions that are o90% conserved in mammalian species. 21 The only exception is the 12308 transition, which falls in a tRNA-conserved region; however, it is not considered pathogenic, as it is diagnostic of haplogroups U and K, and an increased frequency among SZ patients of these two haplogroups have never been reported.…”

Biogenesis of glutaminyl-mt tRNA Gln in human mitochondria

“…However, unlike other mt tRNAs, mammalian mt tRNA Gln species commonly have the canonical D-and T-loops, containing a G18G19 D-loop and U54U55C56 T-loop sequence (Fig. S5) (38). Although the complex structure of GatCAB-tRNA Gln is not available, considering that GatCAB strictly recognizes the number of bases in the D-loop of tRNA Gln (24), we suggest that hGatCAB recognizes the canonical D-loop/T-loop interaction of mt tRNA Gln .…”

A mechanism for functional segregation of mitochondrial and cytosolic genetic codes

“…This seems to be accompanied by a process of size reduction in mitochondrial ARS (20,21) and a dramatic divergence in the structure of tRNAs (22). The elimination of tRNA genes in Kinetoplastida mitochondria may be seen as another example of integration of the cell's genetic codes.…”