title: The third subunit of desulfoviridin-type dissimilatory sulfite reductases.
abstract: In addition to the 50-kDa (alpha) and 40-kDa (beta) subunits, an 11-kDa polypeptide has been discovered in highly purified Desulfovibrio vulgaris (Hildenborough) dissimilatory sulfite reductase. This is in contrast with the hitherto generally accepted alpha 2 beta 2 tetrameric subunit composition. Purification, high-ionic-strength gel-filtration, native electrophoresis and isoelectric focussing do not result in dissociation of the 11-kDa polypeptide from the complex. Densitometric scanning of SDS gels and denaturing gel-filtration indicate a stoichiometric occurrence. A similar 11-kDa polypeptide is present in the desulfoviridin of D. vulgaris oxamicus (Monticello), D. gigas and D. desulfuricans ATCC 27774. We attribute an alpha 2 beta 2 gamma 2 subunit structure to desulfoviridin-type sulfite reductases. N-terminal sequences of the alpha, beta and gamma subunits are reported.
authors.affiliation: Department of Biochemistry, Agricultural University, Wageningen, The Netherlands.
authors.forename: A J
authors.initials: AJ
authors.lastname: Pierik
authors.forename: M G
authors.initials: MG
authors.lastname: Duyvis
authors.forename: J M
authors.initials: JM
authors.lastname: van Helvoort
authors.forename: R B
authors.initials: RB
authors.lastname: Wolbert
authors.forename: W R
authors.initials: WR
authors.lastname: Hagen
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002850:Chromatography, Gel; D003901:Desulfovibrio / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry* / Q000276:immunology
chemical_list: D050862:Oxidoreductases Acting on Sulfur Group Donors