title: X-ray structure of the [FeFe]-hydrogenase maturase HydE from Thermotoga maritima.
abstract: Maturation of the [FeFe]-hydrogenase active site depends on at least the expression of three gene products called HydE, HydF, and HydG. We have solved the high resolution structure of recombinant, reconstituted S-adenosine-L-methionine-dependent HydE from Thermotoga maritima. Besides the conserved [Fe(4)S(4)] cluster involved in the radical-based reaction, this HydE was reported to have a second [Fe(4)S(4)] cluster coordinated by three Cys residues. However, in our crystals, depending on the reconstitution and soaking conditions, this second cluster is either a [Fe(2)S(2)] center, with water occupying the fourth ligand site or is absent. We have carried out site-directed mutagenesis studies on the related HydE from Clostridium acetobutylicum, along with in silico docking and crystal soaking experiments, to define the active site region and three anion-binding sites inside a large, positive cavity, one of which binds SCN(-) with high affinity. Although the overall triose-phosphate isomerase-barrel structure of HydE is very similar to that of biotin synthase, the residues that line the internal cavity are significantly different in the two enzymes.
authors.affiliation: Laboratoire de Cristallographie et Cristallogenèse des Protéines, Institut de Biologie Structurale J.P. Ebel, Commissariat à l'Energie Atomique, CNRS, Université J. Fourier, 41 Rue J. Horowitz, 38027 Grenoble Cedex 1, France.
authors.forename: Yvain
authors.initials: Y
authors.lastname: Nicolet
authors.forename: Jon K
authors.initials: JK
authors.lastname: Rubach
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Posewitz
authors.forename: Patricia
authors.initials: P
authors.lastname: Amara
authors.forename: Carole
authors.initials: C
authors.lastname: Mathevon
authors.forename: Mohamed
authors.initials: M
authors.lastname: Atta
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
authors.forename: Juan C
authors.initials: JC
authors.lastname: Fontecilla-Camps
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites / Q000502:physiology; D046969:Clostridium acetobutylicum / Q000201:enzymology / Q000235:genetics; D018360:Crystallography, X-Ray; D005001:Ethionine / Q000031:analogs & derivatives / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005609:Free Radicals / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000737:chemistry* / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D040681:Structural Homology, Protein; D020124:Thermotoga maritima / Q000201:enzymology* / Q000235:genetics; D014867:Water / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005609:Free Radicals; D007506:Iron-Sulfur Proteins; D011994:Recombinant Proteins; D014867:Water; C012167:S-adenosylethionine; D007501:Iron; D000241:Adenosine; D005001:Ethionine