Linked Life Data

7691984

Source:http://linkedlifedata.com/resource/pubmed/id/7691984

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1993-11-24
pubmed:databankReference
pubmed:abstractText
A dissimilatory sulphite reductase was isolated from the extremely thermophilic dissimilatory sulphate-reducing archaeon Archaeoglobus fulgidus. In common with other dissimilatory sulphite reductases thus far characterized, the enzyme has an alpha 2 beta 2-structure and contains sirohaem, non-haem iron atoms and acid labile sulphide. The oxidized enzyme exhibited absorption maxima at 281, 394, 545 and 593 nm with a weak band around 715 nm. We have cloned and sequenced the genes for the alpha and beta subunits of this enzyme, which we designate dsrA and dsrB, respectively. They are contiguous in the order dsrA dsrB and probably comprise an operon, since dsrA is preceded by sequences characteristic of promoters in methanogenic archaea, and dsrB is followed by a sequence resembling termination signals in extremely thermophilic sulphur-dependent archaea. dsrA and dsrB encode 47.4 kDa and 41.7 kDa peptides, which have 25.6% amino acid sequence identity, indicating that they may have arisen by duplication of an ancestral gene. Each deduced peptide contains cysteine clusters resembling those postulated to bind sirohaem-[Fe4S4] complexes in sulphite reductases and nitrite reductases from other species. The dsrB encoded peptide lacks a single cysteine residue in one of the two clusters, suggesting that only the alpha subunit binds a sirohaem-[Fe4S4] complex, and chemical analyses showed the presence of only two sirohaems per alpha 2 beta 2 enzyme molecule. Both deduced peptides also contain an arrangement of cysteine residues characteristic of [Fe4S4] ferredoxins, and chemical analyses were consistent with the presence of six [Fe4S4] clusters per alpha 2 beta 2 enzyme molecule, two of which would be expected to be associated with sirohaem while the other four could bind to the ferredoxin-like sites.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-1287
pubmed:author
pubmed:issnType
Print
pubmed:volume
139
pubmed:geneSymbol
dsrA, dsrB
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1817-28
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Dissimilatory sulphite reductase from Archaeoglobus fulgidus: physico-chemical properties of the enzyme and cloning, sequencing and analysis of the reductase genes.
pubmed:affiliation
Institut für Mikrobiologie und Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't