The structure of hydrogenase-2 from Escherichia coli: implications for H2-driven proton pumping.
Stephen E BeatonRhiannon M EvansAlexander J FinneyCiaran M LamontFraser A ArmstrongFrank SargentStephen B CarrPublished in: The Biochemical journal (2018)
Under anaerobic conditions, Escherichia coli is able to metabolize molecular hydrogen via the action of several [NiFe]-hydrogenase enzymes. Hydrogenase-2, which is typically present in cells at low levels during anaerobic respiration, is a periplasmic-facing membrane-bound complex that functions as a proton pump to convert energy from hydrogen (H2) oxidation into a proton gradient; consequently, its structure is of great interest. Empirically, the complex consists of a tightly bound core catalytic module, comprising large (HybC) and small (HybO) subunits, which is attached to an Fe-S protein (HybA) and an integral membrane protein (HybB). To date, efforts to gain a more detailed picture have been thwarted by low native expression levels of Hydrogenase-2 and the labile interaction between HybOC and HybA/HybB subunits. In the present paper, we describe a new overexpression system that has facilitated the determination of high-resolution crystal structures of HybOC and, hence, a prediction of the quaternary structure of the HybOCAB complex.
Keyphrases
- escherichia coli
- high resolution
- microbial community
- wastewater treatment
- induced apoptosis
- electron transfer
- poor prognosis
- visible light
- mass spectrometry
- cell cycle arrest
- sewage sludge
- hydrogen peroxide
- nitric oxide
- klebsiella pneumoniae
- oxidative stress
- biofilm formation
- staphylococcus aureus
- quality improvement
- solid phase extraction
- candida albicans
- metal organic framework