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.
Urich
Tim
T
Darmstadt University of Technology, Institute of Microbiology and Genetics, Schnittspahnstrasse 10, 64287 Darmstadt, Germany.
Gomes
Cláudio M
CM
Kletzin
Arnulf
A
Frazão
Carlos
C
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