Substrate Pathways and Mechanisms of Inhibition in the Sulfur Oxygenase Reductase of Acidianus Ambivalens.
Veith, A., Urich, T., Seyfarth, K., Protze, J., Frazao, C., Kletzin, A.(2011) Front Microbiol 2: 37
- PubMed: 21747782 
- DOI: https://doi.org/10.3389/fmicb.2011.00037
- Primary Citation of Related Structures:  
2YAV, 2YAW, 2YAX - PubMed Abstract: 
The sulfur oxygenase reductase (SOR) is the initial enzyme of the sulfur oxidation pathway in the thermoacidophilic Archaeon Acidianus ambivalens. The SOR catalyzes an oxygen-dependent sulfur disproportionation to H(2)S, sulfite and thiosulfate. The spherical, hollow, cytoplasmic enzyme is composed of 24 identical subunits with an active site pocket each comprising a mononuclear non-heme iron site and a cysteine persulfide. Substrate access and product exit occur via apolar chimney-like protrusions at the fourfold symmetry axes, via narrow polar pores at the threefold symmetry axes and via narrow apolar pores within in each subunit. In order to investigate the function of the pores we performed site-directed mutagenesis and inhibitor studies.
Organizational Affiliation: 
Institute of Microbiology and Genetics, Technische Universität Darmstadt Darmstadt, Germany.