Abstract
To gain an understanding of structural changes induced in substrates by Escherichia coli ribonuclease P (RNase P), we have incorporated an interstrand disulfide crosslink proximal to the cleavage site in a model substrate. RNase P is able to process the reduced, non-crosslinked form of this substrate as well as a substrate in which the free thiol molecules have been alkylated with iodoacetamide. However, the oxidized, crosslinked form is cleaved at a significantly lower rate. Therefore, helical unwinding of the analog of the aminoacyl stem of the substrate near its site of cleavage may be necessary for efficient processing by E. coli RNase P.
Copyright 2000 Academic Press.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alkylating Agents / metabolism
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Alkylation
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Base Pairing / genetics*
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Base Sequence
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Disulfides / chemistry
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Disulfides / metabolism*
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Endoribonucleases / metabolism*
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Escherichia coli / enzymology*
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Escherichia coli Proteins*
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Holoenzymes / metabolism
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Iodoacetamide / metabolism
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Kinetics
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Models, Genetic
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Models, Molecular
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Oxidation-Reduction
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RNA Processing, Post-Transcriptional
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RNA, Catalytic / metabolism*
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RNA, Fungal / chemical synthesis
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RNA, Fungal / chemistry
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RNA, Fungal / genetics
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RNA, Fungal / metabolism
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RNA, Transfer, Phe / chemical synthesis
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RNA, Transfer, Phe / chemistry*
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RNA, Transfer, Phe / genetics
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RNA, Transfer, Phe / metabolism*
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Ribonuclease P
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Saccharomyces cerevisiae / genetics
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Substrate Specificity
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Sulfhydryl Compounds / chemistry
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Sulfhydryl Compounds / metabolism
Substances
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Alkylating Agents
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Disulfides
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Escherichia coli Proteins
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Holoenzymes
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RNA, Catalytic
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RNA, Fungal
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RNA, Transfer, Phe
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Sulfhydryl Compounds
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Endoribonucleases
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Ribonuclease P
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ribonuclease P, E coli
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Iodoacetamide