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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2002-5-29
pubmed:abstractText
NAD(P)(+)-reducing hydrogenases have been described to be composed of a diaphorase (HoxFU) and a hydrogenase (HoxYH) moiety. This study presents for the first time experimental evidence that in cyanobacteria, a fifth subunit, HoxE, is part of this bidirectional hydrogenase. HoxE exhibits sequence identities to NuoE of respiratory complex I of Escherichia coli. The subunit composition of the cyanobacterial bidirectional hydrogenase has been investigated. The oxygen labile enzyme complex was purified to close homogeneity under anaerobic conditions from Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 6301. The 647-fold and 1290-fold enriched purified enzyme has a specific activity of 46 micromol H(2) evolved (min mg protein)(-1) and 15 micromol H(2) evolved (min mg protein)(-1), respectively. H(2)-evolution of the purified enzyme of S. sp. PCC 6803 is highest at 60 degrees C and pH 6.3. Immunoblot experiments, using a polyclonal anti-HoxE antibody, demonstrate that HoxE co-purifies with the hydrogenase activity in S. sp. PCC 6301. SDS-PAGE gels of the purified enzymes revealed six proteins, which were partially sequenced and identified, besides one nonhydrogenase component, as HoxF, HoxU, HoxY, HoxH and, remarkably, HoxE. The molecular weight of the native protein (375 kDa) indicates a dimeric assembly of the enzyme complex, Hox(EFUYH)(2).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
1554
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
66-74
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
HoxE--a subunit specific for the pentameric bidirectional hydrogenase complex (HoxEFUYH) of cyanobacteria.
pubmed:affiliation
Botanisches Institut der Universität Köln, Gyrhofstr. 15, D-50931 Cologne, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't