Oxford University Press;England: Oxford University Press
摘要:
摘要： In eukaryotes, the cytoplasmic and mitochondrial forms of a given aminoacyl-tRNA synthetase (aaRS) are typically encoded by two orthologous nuclear genes, one of eukaryotic origin and the other of mitochondrial origin. We herein report a novel scenario of aaRS evolution in yeast. While all other yeast species studied possess a single nuclear gene encoding both forms of alanyl-tRNA synthetase (AlaRS), Vanderwaltozyma polyspora, a yeast species descended from the same whole-genome duplication event as Saccharomyces cerevisiae, contains two distinct nuclear AlaRS genes, one specifying the cytoplasmic form and the other its mitochondrial counterpart. The protein sequences of these two isoforms are very similar to each other. The isoforms are actively expressed in vivo and are exclusively localized in their respective cellular compartments. Despite the presence of a promising AUG initiator candidate, the gene encoding the mitochondrial form is actually initiated from upstream non-AUG codons. A phylogenetic analysis further revealed that all yeast AlaRS genes, including those in V. polyspora, are of mitochondrial origin. These findings underscore the possibility that contemporary AlaRS genes in V. polyspora arose relatively recently from duplication of a dual-functional predecessor of mitochondrial origin. 其他題名： Nucleic Acids Res 出版者： England: Oxford University Press 出版日期： 2012-01-01 出處： Nucleic acids research, 2012-01, Vol.40 (1), p.314-322 資源來源： Oxford Journals Open Access Collection 版權： The Author(s) 2011. Published by Oxford University Press. 2011 識別號： ISSN: 0305-1048 識別號： ISSN: 1362-4962 識別號： ISSN: 1362-4954 識別號： EISSN: 1362-4962 識別號： DOI: 10.1093/nar/gkr724 識別號： PMID: 21908394
