Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
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Target Concepts:
Gene/Protein
Disease
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Enzyme
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Query: EC:3.6.3.14 (
ATP synthase
)
7,042
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The organization of the
membrane-bound hydrogenase
from Escherichia coli was studied by using two membrane-impermeant probes, diazotized [125I]di-iodosulphanilic acid and lactoperoxidase-catalysed radioiodination. The labelling pattern of the enzyme obtained from labelled spheroplasts was compared with that from predominantly inside-out membrane vesicles, after recovery of hydrogenase by immunoprecipitation. The labelling pattern of
F1-ATPase
was used as a control for labelling at the cytoplasmic surface throughout these experiments. Hydrogenase (mol.wt. approx. 63 000) is transmembranous. Crossed immunoelectrophoresis with anti-(membrane vesicle) immunoglobulins, coupled with successive immunoadsorption of the antiserum with spheroplasts, confirmed the location of hydrogenase at the periplasmic surface. Immunoadsorption with sonicated spheroplasts suggests that the enzyme is also exposed at the cytoplasmic surface. Inside-out vesicles were prepared by agglutination of sonicated spheroplasts, and the results of immunoadsorption using these vesicles confirms the location of hydrogenase at the cytoplasmic surface.
...
PMID:The organization of hydrogenase in the cytoplasmic membrane of Escherichia coli. 703 17
Syntrophic butyrate metabolism involves the thermodynamically unfavorable production of hydrogen and/or formate from the high potential electron donor, butyryl-CoA. Such redox reactions can occur only with energy input by a process called reverse electron transfer. Previous studies have demonstrated that hydrogen production from butyrate requires the presence of a proton gradient, but the biochemical machinery involved has not been clearly elucidated. In this study, the gene and enzyme systems involved in reverse electron transfer by
Syntrophomonas wolfei
were investigated using proteomic and gene expression approaches.
S. wolfei
was grown in co-culture with
Methanospirillum hungatei
or
Dehalococcoides mccartyi
under conditions requiring reverse electron transfer and compared to both axenic
S. wolfei
cultures and co-cultures grown in conditions that do not require reverse electron transfer. Blue native gel analysis of membranes solubilized from syntrophically grown cells revealed the presence of a
membrane-bound hydrogenase
, Hyd2, which exhibited hydrogenase activity during in gel assays. Bands containing a putative iron-sulfur (FeS) oxidoreductase were detected in membranes of crotonate-grown and butyrate grown
S. wolfei
cells. The genes for the corresponding hydrogenase subunits,
hyd2ABC
, were differentially expressed at higher levels during syntrophic butyrate growth when compared to growth on crotonate. The expression of the FeS oxidoreductase gene increased when
S. wolfei
was grown with
M. hungatei
. Additional membrane-associated proteins detected included F
o
F
1
ATP synthase
subunits and several membrane transporters that may aid syntrophic growth. Furthermore, syntrophic butyrate metabolism can proceed exclusively by interspecies hydrogen transfer, as demonstrated by growth with
D. mccartyi
, which is unable to use formate. These results argue for the importance of Hyd2 and FeS oxidoreductase in reverse electron transfer during syntrophic butyrate degradation.
...
PMID:Membrane Complexes of
Syntrophomonas wolfei
Involved in Syntrophic Butyrate Degradation and Hydrogen Formation. 2788 75
