Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich.
mehr Informationen...
Efficient electron transfer from hydrogen to benzyl viologen by the [NiFe]-hydrogenases of Escherichia coli is dependent on the coexpression of the iron–sulfur cluster-containing small subunit
Ist Teil von
Archives of microbiology, 2011-12, Vol.193 (12), p.893-903
Ort / Verlag
Berlin/Heidelberg: Springer-Verlag
Erscheinungsjahr
2011
Link zum Volltext
Quelle
SpringerLink (Online service)
Beschreibungen/Notizen
Escherichia coli
can both oxidize hydrogen and reduce protons. These activities involve three distinct [NiFe]-hydrogenases, termed Hyd-1, Hyd-2, and Hyd-3, each minimally comprising heterodimers of a large subunit, containing the [NiFe] active site, and a small subunit, bearing iron–sulfur clusters. Dihydrogen-oxidizing activity can be determined using redox dyes like benzyl viologen (BV); however, it is unclear whether electron transfer to BV occurs directly at the active site, or via an iron–sulfur center in the small subunit. Plasmids encoding Strep-tagged derivatives of the large subunits of the three
E. coli
[NiFe]-hydrogenases restored activity of the respective hydrogenase to strain FTD147, which carries in-frame deletions in the
hyaB, hybC,
and
hycE
genes encoding the large subunits of Hyd-1, Hyd-2, and Hyd-3, respectively. Purified Strep-HyaB was associated with the Hyd-1 small subunit (HyaA), and purified Strep-HybC was associated with the Hyd-2 small subunit (HybO), and a second iron–sulfur protein, HybA. However, Strep-HybC isolated from a
hybO
mutant had no other associated subunits and lacked BV-dependent hydrogenase activity. Mutants deleted separately for
hyaA
,
hybO,
or
hycG
(Hyd-3 small subunit) lacked BV-linked hydrogenase activity, despite the Hyd-1 and Hyd-2 large subunits being processed. These findings demonstrate that hydrogenase-dependent reduction of BV requires the small subunit.