Abstract
Several phosphorothioate-modified E coli and yeast pre-tRNAs were synthesized. If this modification included the phosphodiester at the RNase P cleavage site, two different effects were observed. With some pre-tRNAs the RNase P cleavage efficiency was severely reduced, whereas with other pre-tRNAs a new reaction type for RNase P was observed. Unlike the previously studied base or ribose modifications, phosphorothioates resulted in aberrant cleavages at unmodified phosphodiesters. These new sites could be located in the 5'-flank or in the acceptor stem of the tRNA domain. Modified mutants of E coli pre-tRNA(Tyr) with different base pairs at the RNase P cleavage site were cleaved with reduced efficiencies, but no aberrant products were observed.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Base Composition
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Base Sequence
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Endoribonucleases / metabolism*
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Escherichia coli / genetics
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Escherichia coli Proteins*
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Molecular Sequence Data
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Mutation
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RNA Precursors / chemistry
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RNA Precursors / genetics
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RNA Precursors / metabolism*
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RNA, Catalytic / metabolism*
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RNA, Transfer / chemistry
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RNA, Transfer / genetics
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RNA, Transfer / metabolism*
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RNA, Transfer, Amino Acyl / chemistry
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RNA, Transfer, Amino Acyl / genetics
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RNA, Transfer, Amino Acyl / metabolism
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Ribonuclease P
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Thionucleosides / chemistry
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Thionucleosides / metabolism*
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Transcription, Genetic
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Yeasts / genetics
Substances
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Escherichia coli Proteins
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RNA Precursors
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RNA, Catalytic
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RNA, Transfer, Amino Acyl
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Thionucleosides
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RNA, Transfer
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Endoribonucleases
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Ribonuclease P
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ribonuclease P, E coli