3lx4: Difference between revisions
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<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/lx/3lx4_consurf.spt"</scriptWhenChecked> | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/lx/3lx4_consurf.spt"</scriptWhenChecked> | ||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> |
Revision as of 10:02, 9 January 2019
Stepwise [FeFe]-hydrogenase H-cluster assembly revealed in the structure of HydA(deltaEFG)Stepwise [FeFe]-hydrogenase H-cluster assembly revealed in the structure of HydA(deltaEFG)
Structural highlights
Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedComplex enzymes containing Fe-S clusters are ubiquitous in nature, where they are involved in a number of fundamental processes including carbon dioxide fixation, nitrogen fixation and hydrogen metabolism. Hydrogen metabolism is facilitated by the activity of three evolutionarily and structurally unrelated enzymes: the [NiFe]-hydrogenases, [FeFe]-hydrogenases and [Fe]-hydrogenases (Hmd). The catalytic core of the [FeFe]-hydrogenase (HydA), termed the H-cluster, exists as a [4Fe-4S] subcluster linked by a cysteine thiolate to a modified 2Fe subcluster with unique non-protein ligands. The 2Fe subcluster and non-protein ligands are synthesized by the hydrogenase maturation enzymes HydE, HydF and HydG; however, the mechanism, synthesis and means of insertion of H-cluster components remain unclear. Here we show the structure of HydA(DeltaEFG) (HydA expressed in a genetic background devoid of the active site H-cluster biosynthetic genes hydE, hydF and hydG) revealing the presence of a [4Fe-4S] cluster and an open pocket for the 2Fe subcluster. The structure indicates that H-cluster synthesis occurs in a stepwise manner, first with synthesis and insertion of the [4Fe-4S] subcluster by generalized host-cell machinery and then with synthesis and insertion of the 2Fe subcluster by specialized hydE-, hydF- and hydG-encoded maturation machinery. Insertion of the 2Fe subcluster presumably occurs through a cationically charged channel that collapses following incorporation, as a result of conformational changes in two conserved loop regions. The structure, together with phylogenetic analysis, indicates that HydA emerged within bacteria most likely from a Nar1-like ancestor lacking the 2Fe subcluster, and that this was followed by acquisition in several unicellular eukaryotes. Stepwise [FeFe]-hydrogenase H-cluster assembly revealed in the structure of HydA(DeltaEFG).,Mulder DW, Boyd ES, Sarma R, Lange RK, Endrizzi JA, Broderick JB, Peters JW Nature. 2010 May 13;465(7295):248-51. Epub 2010 Apr 25. PMID:20418861[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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