Transfer RNA genes inDrosophilamitochondrial DNA: related 5' flanking sequences and comparisons to mammalian mitochondrial tRNA genes

Abstract

Genes for tRNAglY and tRNAser have been identified within sequences of mtDNA of Drosophila yakuba. The tRNAglY gene lies between the genes for cytochrome c oxidase subunit III and URF3, and all three of these genes are contained in the same strand of the mtDNA molecule. The tRNAqC gene is adjacent to the URF1 gene. These genes are contained in opposite strands f the mtDNA molecule and their 3' ends overlap. The structures of the tRNA9YT and tRNA ser gejes, and gf the f?ur tRNA genes of D. yakuba mtDNA reported earlier U(fNAi e, tRNA n, tRNA -me and tRNAva )Fare compared to each other, to non-organelle tRNAs, and to corresponding mammalian mitochondrial tRNA genes. Within 19 nucleotides upstream froqi the 5' terminal. ucleotide of each of the Drosophila mitochondrial tRNAlY, tRN tRNAI e, tRNA9n and tRNA -meL genes occurs the sequence 5'TTTATTAT, or a sequence differing from it by one nucleotide substitution. Upstream from this octanucleotide sequence, and separated from it by 3, 4 and 11 nucleotides, respectively, in the 5' flanking regions of the tRNAlle, tRNAser and tRNAJy genes occurs the sequence 5'GATGAG. INTRODUCTIONThe nucleotide sequence of the whole mitochondrial DNA (mtDNA) molecule of each of three mammals, human, bovine and mouse, has been completed (1-3).

Complete mtDNA Sequences of Two Millipedes Suggest a New Model for Mitochondrial Gene Rearrangements: Duplication and Nonrandom Loss

“…We assume that the original mitochondrial genome had a gene arrangement identical to that in Limulus polyphemus, which appears to be ancestral for arthropods (Lavrov, Boore, and Brown, 2000; unpublished data), and that both of the mtDNA strands were transcribed in their entirety either from the same bi-directional promoter or from two unidirectional promoters, both located in the same non-coding region. Such arrangements have been found in vertebrate mtDNAs, in which most studies on mitochondrial transcription mechanisms have been conducted (Tracy and Stern 1995), and are consistent with the generally observed scarcity of intergenic sequences in arthropod mitochondrial genomes that otherwise could serve as transcriptional promoters (but see Clary, Wahleithner, and Wolstenholme 1983).…”

Cloning and chromosomal localization of a cDNA encoding a mitochondrial porin from Drosophila melanogaster

“…The antiserum was highly reactive against Drosophila porin, as assessed by ELISA assay ( A. Messina et alIFEBS Letters 384 (1996) The sequence was chimeric: it showed the presence of the Y-terminal part of an unknown message curiously fused with bp 45194954 of the sequence of D. melanogaster CitOx subunit III, which is mitochondrially encoded, until a native EcoRI site (49494954) [24,25]. The cDNA sequence fused to the CitOx subunit was an open reading frame for the C-terminus of a protein.…”

A cluster of six tRNA genes inDrosophilamitochondrial DNA that includes a gene for an unusual tRNAserAGY

“…(mtDNA) molecule of Drosophila yakuba we have identified and reported the genes for two ribosomal RNAs, twelve tRNAs and eight polypeptides (cytochrome c oxidase (CO) subunits I, II and III, ATPase subunit 6, Unidentified Reading Frames (URF) 1, 2 and 3 and A6L) (1)(2)(3)(4). Nucleotide sequences of sections of the D. melanogaster mtDNA molecule, corresponding to some of the sequenced sections of the D. yakuba mtDNA molecule have also been determined (1,2,5).…”

“…(mtDNA) molecule of Drosophila yakuba we have identified and reported the genes for two ribosomal RNAs, twelve tRNAs and eight polypeptides (cytochrome c oxidase (CO) subunits I, II and III, ATPase subunit 6, Unidentified Reading Frames (URF) 1, 2 and 3 and A6L) (1)(2)(3)(4). Nucleotide sequences of sections of the D. melanogaster mtDNA molecule, corresponding to some of the sequenced sections of the D. yakuba mtDNA molecule have also been determined (1,2,5). While the genes found in Drosophila mtDNAs are the same as the genes found in a number of mamnalian mtDNAs (6)(7)(8), their arrangement within the Drosophila and mammalian mtDNA molecules differs considerably (1)(2)(3)(4)(5).…”

“…Nucleotide sequences of sections of the D. melanogaster mtDNA molecule, corresponding to some of the sequenced sections of the D. yakuba mtDNA molecule have also been determined (1,2,5). While the genes found in Drosophila mtDNAs are the same as the genes found in a number of mamnalian mtDNAs (6)(7)(8), their arrangement within the Drosophila and mammalian mtDNA molecules differs considerably (1)(2)(3)(4)(5). Also, evidence obtained from comparisons of sequences of Drosophila and mammalian polypeptide genes suggests that in the Drosophila mitochondrial genetic code the triplet AGA, which specifies arginine in the standard genetic code, and is used only as a rare termination codon in some mammalian mtDNAs (6)(7)(8), may specify serine (3-C I RL Press Limited, Oxford, England.…”