Linked Life Data

15134447

Source:http://linkedlifedata.com/resource/pubmed/id/15134447

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2004-5-11
pubmed:abstractText
Carbon monoxide dehydrogenase from Moorella thermoacetica catalyzes the reversible oxidation of CO to CO(2) at a nickel-iron-sulfur active site called the C-cluster. Mutants of a proposed proton transfer pathway and of a cysteine residue recently found to form a persulfide bond with the C-cluster were characterized. Four semiconserved histidine residues were individually mutated to alanine. His116 and His122 were essential to catalysis, while His113 and His119 attenuated catalysis but were not essential. Significant activity was "rescued" by a double mutant where His116 was replaced by Ala and His was also introduced at position 115. The activity was also rescued in double mutants where His122 was replaced by Ala and His was simultaneously introduced at either position 121 or position 123. Activity was also rescued by replacing His with Cys at position 116. Mutation of conserved Lys587 near the C-cluster attenuated activity but did not eliminate it. Activity was virtually abolished in a double mutant where Lys587 and His113 were both changed to Ala. Mutations of conserved Asn284 also attenuated activity. These effects suggest the presence of a network of amino acid residues responsible for proton transfer rather than a single linear pathway. The Ser mutant of the persulfide-forming Cys316 was essentially inactive and displayed no electron paramagnetic resonance signals originating from the C-cluster. Electronic absorption and metal analysis suggest that the C-cluster is absent in this mutant. The persulfide bond appears to be essential for either the assembly or the stability of the C-cluster, and possibly for eliciting the redox chemistry of the C-cluster required for catalytic activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Alanine, http://linkedlifedata.com/resource/pubmed/chemical/Aldehyde Oxidoreductases, http://linkedlifedata.com/resource/pubmed/chemical/Asparagine, http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cysteine, http://linkedlifedata.com/resource/pubmed/chemical/Histidine, http://linkedlifedata.com/resource/pubmed/chemical/Lysine, http://linkedlifedata.com/resource/pubmed/chemical/Multienzyme Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Nickel, http://linkedlifedata.com/resource/pubmed/chemical/Protons, http://linkedlifedata.com/resource/pubmed/chemical/Serine, http://linkedlifedata.com/resource/pubmed/chemical/Sulfides, http://linkedlifedata.com/resource/pubmed/chemical/carbon monoxide dehydrogenase, http://linkedlifedata.com/resource/pubmed/chemical/persulfides
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5728-34
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Evidence for a proton transfer network and a required persulfide-bond-forming cysteine residue in Ni-containing carbon monoxide dehydrogenases.
pubmed:affiliation
Department of Chemistry, Texas A&M University, Post Office Box 30012, College Station, Texas 77842-3012, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.