Abstract
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.
Publication types
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acyl-tRNA Synthetases / chemistry
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Amino Acyl-tRNA Synthetases / genetics
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Amino Acyl-tRNA Synthetases / isolation & purification
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Amino Acyl-tRNA Synthetases / metabolism*
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Binding Sites
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Cysteine / metabolism
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Cysteine / pharmacology
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Escherichia coli / genetics
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Escherichia coli / growth & development
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Evolution, Molecular
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Genes, Archaeal
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Methanococcus / enzymology*
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Methanococcus / genetics
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Multienzyme Complexes / chemistry
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Multienzyme Complexes / genetics
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Multienzyme Complexes / isolation & purification
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Multienzyme Complexes / metabolism*
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Proline / metabolism
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Proline / pharmacology
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RNA, Transfer, Amino Acyl / biosynthesis*
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Sequence Analysis, Protein
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Substrate Specificity
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Transfer RNA Aminoacylation
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Transformation, Bacterial
Substances
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Multienzyme Complexes
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RNA, Transfer, Amino Acyl
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Proline
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Amino Acyl-tRNA Synthetases
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prolyl T RNA synthetase
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cysteinyl-tRNA synthetase
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Cysteine