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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
5
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pubmed:dateCreated |
1984-5-2
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pubmed:abstractText |
Pyruvate formate-lyase (formate acetyltransferase; EC 2.3.1.54) of Escherichia coli cells is post-translationally interconverted between inactive and active forms. Conversion of the inactive to the active form is catalyzed by an Fe2+-dependent activating enzyme and requires adenosylmethionine and dihydroflavodoxin. This process is shown here to introduce a paramagnetic moiety into the structure of pyruvate formate-lyase. It displays an EPR signal at g = 2 with a doublet splitting of 1.5 mT and could comprise an organic free radical located on an amino acid residue of the polypeptide chain. Hypophosphite was discovered as a specific reagent that destroys both the enzyme radical and the enzyme activity; it becomes covalently bound to the protein. The enzymatic generation of the radical, which is linked to adenosylmethionine cleavage into 5'-deoxyadenosine and methionine, possibly occurs through an Fe-adenosyl complex. These results suggest a radical mechanism for the catalytic cycle of pyruvate formate-lyase.
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pubmed:commentsCorrections |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0027-8424
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
81
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1332-5
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:6369325-Acetyltransferases,
pubmed-meshheading:6369325-Carbon Radioisotopes,
pubmed-meshheading:6369325-Enzyme Activation,
pubmed-meshheading:6369325-Escherichia coli,
pubmed-meshheading:6369325-Free Radicals,
pubmed-meshheading:6369325-Kinetics,
pubmed-meshheading:6369325-Phosphinic Acids,
pubmed-meshheading:6369325-Phosphorus Radioisotopes,
pubmed-meshheading:6369325-Protein Processing, Post-Translational,
pubmed-meshheading:6369325-S-Adenosylmethionine,
pubmed-meshheading:6369325-Tritium
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pubmed:year |
1984
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pubmed:articleTitle |
Post-translational activation introduces a free radical into pyruvate formate-lyase.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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