title: A protein isolated from Brucella abortus is a Cu-Zn superoxide dismutase.
abstract: Brucella abortus contains a protein that elicits an antigenic response in cattle previously exposed to the organism. The amino acid sequence of the recombinant form of this antigenic protein was determined by gas-phase sequencing of the pyridylethylated protein and its peptides obtained by digestion with cyanogen bromide (CNBr), clostripain, and Staphylococcus aureus V8 protease. The Brucella protein demonstrated 53.6% identity with the Cu-Zn superoxide dismutase (SOD) from Photobacterium leiognathi. Residues essential for metal coordination and enzymatic activity and cysteines required for the formation of the intrasubunit disulfide bridge of Cu-Zn SOD were conserved in the Brucella protein. also exhibited SOD activity that was inhibited by cyanide, which is characteristic of a Cu-Zn SOD. Brucella abortus Cu-Zn SOD is the second prokaryotic Cu-Zn SOD to be sequenced, and the fifth found in prokaryotes. The high degree of conservation between Photobacterium and Brucella Cu-Zn SOD supports the hypothesis of a separately evolved prokaryotic and eukaryotic Cu-Zn SOD gene.
authors.affiliation: U.S. Department of Agriculture, National Animal Disease Center, Ames, Iowa 50010.
authors.forename: B L
authors.initials: BL
authors.lastname: Beck
authors.forename: L B
authors.initials: LB
authors.lastname: Tabatabai
authors.forename: J E
authors.initials: JE
authors.lastname: Mayfield
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002003:Brucella abortus / Q000201:enzymology*; D003488:Cyanogen Bromide; D003546:Cysteine Endopeptidases; D008969:Molecular Sequence Data; D010446:Peptide Fragments; D012689:Sequence Homology, Nucleic Acid; D012697:Serine Endopeptidases; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D013482:Superoxide Dismutase; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D003546:Cysteine Endopeptidases; C019913:clostripain; D003488:Cyanogen Bromide