Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.12.7.2 (
hydrogenase
)
3,522
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Trabulsiella guamensis
is a nonpathogenic enterobacterium that was isolated from a vacuum cleaner on the island of Guam. It has one H
2
-oxidizing Hyd-2-type
hydrogenase
(Hyd) and encodes an H
2
-evolving Hyd that is most similar to the uncharacterized
Escherichia coli
formate hydrogenlyase (FHL-2
Ec
) complex. The
T. guamensis
FHL-2 (FHL-2
Tg
) complex is predicted to have 5 membrane-integral and between 4 and 5 cytoplasmic subunits. We showed that the FHL-2
Tg
complex catalyzes the disproportionation of formate to CO
2
and H
2
FHL-2
Tg
has activity similar to that of the
E. coli
FHL-1
Ec
complex in H
2
evolution from formate, but the complex appears to be more labile upon cell lysis. Cloning of the entire 13-kbp FHL-2
Tg
operon in the heterologous
E. coli
host has now enabled us to unambiguously prove FHL-2
Tg
activity, and it allowed us to characterize the FHL-2
Tg
complex biochemically. Although the formate dehydrogenase (FdhH) gene
fdhF
is not contained in the operon, the FdhH is part of the complex, and FHL-2
Tg
activity was dependent on the presence of
E. coli
FdhH. Also, in contrast to
E. coli
,
T. guamensis
can ferment the alternative carbon source cellobiose, and we further investigated the participation of both the H
2
-oxidizing Hyd-2
Tg
and the H
2
-forming FHL-2
Tg
under these conditions.
IMPORTANCE
Biological H
2
production presents an attractive alternative for fossil fuels. However, in order to compete with conventional H
2
production methods, the process requires our understanding on a molecular level. FHL complexes are efficient H
2
producers, and the prototype
FHL-1
Ec
complex in
E. coli
is well studied. This paper presents the first biochemical characterization of an FHL-2-type complex. The data presented here will enable us to solve the long-standing mystery of the FHL-2
Ec
complex, allow a first biochemical characterization of
T. guamensis
's fermentative metabolism, and establish this enterobacterium as a model organism for FHL-dependent energy conservation.
...
PMID:Dissection of the Hydrogen Metabolism of the Enterobacterium Trabulsiella guamensis: Identification of a Formate-Dependent and Essential Formate Hydrogenlyase Complex Exhibiting Phylogenetic Similarity to Complex I. 3096 55
