X-ray Structure of a self-compartmentalizing sulfur cycle metalloenzyme.
Numerous microorganisms oxidize sulfur for energy conservation and contribute to the global biogeochemical sulfur cycle. We have determined the 1.7 angstrom-resolution structure of the sulfur oxygenase reductase from the thermoacidophilic archaeon Acidianus ambivalens, which catalyzes an oxygen-dependent disproportionation of elemental sulfur. Twenty-four monomers form a large hollow sphere enclosing a positively charged nanocompartment. Apolar channels provide access for linear sulfur species. A cysteine persulfide and a low-potential mononuclear non-heme iron site ligated by a 2-His-1-carboxylate facial triad in a pocket of each subunit constitute the active sites, accessible from the inside of the sphere. The iron is likely the site of both sulfur oxidation and sulfur reduction.
Darmstadt University of Technology, Institute of Microbiology and Genetics, Schnittspahnstrasse 10, 64287 Darmstadt, Germany.
Tim
T
Urich
Cláudio M
CM
Gomes
Arnulf
A
Kletzin
Carlos
C
Frazão
D041541:Acidianus / Q000201:enzymology* / Q000502:physiology; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002384:Catalysis; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D055672:Static Electricity; D013455:Sulfur / Q000378:metabolism*
D019843:Archaeal Proteins; D008024:Ligands; D011994:Recombinant Proteins; D013455:Sulfur; D007501:Iron; D050862:Oxidoreductases Acting on Sulfur Group Donors; C058771:soR protein, Acidianus ambivalens