Open AccessRegulatory properties of O-acetyl-L-serine sulfhydrylase of Cephalosporium acremonium: evidence of an isoenzyme and its importance in cephalosporin C biosynthesis
Author(s) -
Heinz Döbeli,
J. Nüesch
Publication year - 1980
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.18.1.111
Subject(s) - serine , acremonium , biochemistry , methionine , biosynthesis , cysteine , homoserine , enzyme , cephalosporin c , chemistry , residue (chemistry) , amino acid , biology , cephalosporin , gene , antibiotics , botany , quorum sensing , virulence
O-Acetyl-L-serine sulfhydrylase catalyzes the final step in the biosynthesis of cysteine from H2S and O-acetyl-L-serine in the fungus Cephalosporsium acremonium, a cephalosporin C-producing organism. We separated this enzyme from the closely related but less specific O-acetyl-L-homoserine sulfhydrylase and showed that O-acetyl-L-homoserine sulfhydrylase also catalyzes the formation of cysteine from O-acetyl-L-serine and H2S. The expression of O-acetyl-L-serine sulfhydrylase was regulated by exogenous methionine. In addition, this enzyme was inhibited by S-adenosyl-L-methionine and 5-formylpteroyl monoglutamic acid. The inhibition of both S-adenosyl-L-methionine and 5-formylpteroyl monoglutamic acid was noncompetitive. Results obtained with gel filtraton experiments in various buffer systems indicate an association-dissociation behavior of O-acetyl-L-serine sulfhydrylase.