Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
1992-10-7
pubmed:abstractText
The AdhE protein of Escherichia coli is a homopolymer of 96-kDa subunits harboring three Fe(2+)-dependent catalytic functions: acetaldehyde-CoA dehydrogenase, alcohol dehydrogenase, and pyruvate formatelyase (PFL) deactivase. By negative staining electron microscopy, we determined a helical assembly of 20-60 subunits into rods of 45-120 nm in length. The subunit packing is widened along the helix axis when Fe2+ and NAD are present. Chymotrypsin dissects the AdhE polypeptide between Phe762 and Ser763, thereby retaining the alcohol dehydrogenase activity on the NH2-terminal core, but destroying all other activities. PFL deactivation, i.e. quenching of the glycyl radical in PFL by the AdhE protein, was examined with respect to cofactor involvements (Fe2+, NAD, and CoA). This process is coupled to NAD reduction and requires the intact CoA sulfhydryl group. Pyruvate and NADH are inhibitors that affect the steady-state level of the radical form of PFL in a reconstituted interconversion cycle. Studies of cell cultures found that PFL deactivation in situ is initiated at redox potentials of greater than or equal to +100 mV. Our results provide insights into the structure/function organization of the AdhE multienzyme and give a rationale for how its PFL radical quenching activity may be suppressed in situ to enable effective glucose fermentation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Acetyltransferases, http://linkedlifedata.com/resource/pubmed/chemical/Alcohol Dehydrogenase, http://linkedlifedata.com/resource/pubmed/chemical/Aldehyde Oxidoreductases, http://linkedlifedata.com/resource/pubmed/chemical/Chymotrypsin, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Free Radicals, http://linkedlifedata.com/resource/pubmed/chemical/Macromolecular Substances, http://linkedlifedata.com/resource/pubmed/chemical/Multienzyme Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments, http://linkedlifedata.com/resource/pubmed/chemical/adhE protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/formate C-acetyltransferase
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
267
pubmed:geneSymbol
adhE
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18073-9
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:1325457-Acetyltransferases, pubmed-meshheading:1325457-Alcohol Dehydrogenase, pubmed-meshheading:1325457-Aldehyde Oxidoreductases, pubmed-meshheading:1325457-Chymotrypsin, pubmed-meshheading:1325457-Electron Spin Resonance Spectroscopy, pubmed-meshheading:1325457-Escherichia coli, pubmed-meshheading:1325457-Escherichia coli Proteins, pubmed-meshheading:1325457-Free Radicals, pubmed-meshheading:1325457-Genes, Bacterial, pubmed-meshheading:1325457-Kinetics, pubmed-meshheading:1325457-Macromolecular Substances, pubmed-meshheading:1325457-Microscopy, Electron, pubmed-meshheading:1325457-Models, Molecular, pubmed-meshheading:1325457-Molecular Weight, pubmed-meshheading:1325457-Multienzyme Complexes, pubmed-meshheading:1325457-Peptide Fragments, pubmed-meshheading:1325457-Protein Conformation
pubmed:year
1992
pubmed:articleTitle
Ultrastructure and pyruvate formate-lyase radical quenching property of the multienzymic AdhE protein of Escherichia coli.
pubmed:affiliation
Institut für Biologische Chemie, Universität Heidelberg, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't