One polypeptide with two aminoacyl-tRNA synthetase activities.

TitleOne polypeptide with two aminoacyl-tRNA synthetase activities.
Publication TypeJournal Article
Year of Publication2000
AuthorsStathopoulos C, Li T, Longman R, Vothknecht UC, Becker HD, Ibba M, Söll D
Date Published2000 Jan 21
KeywordsAmino Acyl-tRNA Synthetases, Binding Sites, Cysteine, Escherichia coli, Evolution, Molecular, Genes, Archaeal, Methanococcus, Multienzyme Complexes, Proline, RNA, Transfer, Amino Acyl, Sequence Analysis, Protein, Substrate Specificity, Transfer RNA Aminoacylation, Transformation, Bacterial

The genome sequences of certain archaea do not contain recognizable cysteinyl-transfer RNA (tRNA) synthetases, which are essential for messenger RNA-encoded protein synthesis. However, a single cysteinyl-tRNA synthetase activity was detected and purified from one such organism, Methanococcus jannaschii. The amino-terminal sequence of this protein corresponded to the predicted sequence of prolyl-tRNA synthetase. Biochemical and genetic analyses indicated that this archaeal form of prolyl-tRNA synthetase can synthesize both cysteinyl-tRNA(Cys) and prolyl-tRNA(Pro). The ability of one enzyme to provide two aminoacyl-tRNAs for protein synthesis raises questions about concepts of substrate specificity in protein synthesis and may provide insights into the evolutionary origins of this process.

Alternate JournalScience
PubMed ID10642548