Linked Life Data

8161529

Source:http://linkedlifedata.com/resource/pubmed/id/8161529

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
1994-5-26
pubmed:abstractText
The nifS gene product (NIFS) is a pyridoxal phosphate binding enzyme that catalyzes the desulfurization of L-cysteine to yield L-alanine and sulfur. In Azotobacter vinelandii this activity is required for the full activation of the nitrogenase component proteins. Because the nitrogenase component proteins, Fe protein and MoFe protein, both contain metalloclusters which are required for their respective activities, it is suggested that NIFS participates in the biosynthesis of the nitrogenase metalloclusters by providing the inorganic sulfur required for Fe-S core formation [Zheng, L., White, R. H., Cash, V. L. Jack, R. F., & Dean, D. R. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 2754-2758]. In the present study the mechanism for the desulfurization of L-cysteine catalyzed by NIFS was determined in the following ways. First, the substrate analogs, L-allylglycine and vinylglycine, were shown to irreversibly inactivate NIFS by formation of a gamma-methylcystathionyl or cystathionyl residue, respectively, through nucleophilic attack by an active site cysteinyl residue on the corresponding analog-pyridoxal phosphate adduct. Second, this reactive cysteinyl residue, which is required for L-cysteine desulfurization activity, was identified as Cys325 by the specific alkylation of that residue and by site-directed mutagenesis experiments. Third, the formation of an enzyme-bound cysteinyl persulfide was identified as an intermediate in the NIFS-catalyzed reaction. Fourth, evidence was obtained for an enamine intermediate in the formation of L-alanine.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
33
pubmed:geneSymbol
nifS
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4714-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Mechanism for the desulfurization of L-cysteine catalyzed by the nifS gene product.
pubmed:affiliation
Department of Anaerobic Microbiology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.