This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Aharonowitz, Y Articles by Cohen, G Search for Related Content PubMed PubMed Citation Articles by Aharonowitz, Y Articles by Cohen, G

research-article

Characterization of a broad-range disulfide reductase from Streptomyces clavuligerus and its possible role in beta-lactam antibiotic biosynthesis.

Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel.

ABSTRACT

Streptomyces clavuligerus is a potent producer of penicillin and cephalosporin antibiotics. A key step in the biosynthesis of these beta-lactam compounds is the cyclization of the thiol tripeptide delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N by the enzyme isopenicillin N synthase (IPNS). However, bis-ACV, the oxidized disulfide form of the tripeptide, is not a substrate for IPNS. We show here that S. clavuligerus possesses an NADPH-dependent disulfide reductase of broad substrate specificity that efficiently catalyzes the reduction of disulfide bonds in bis-ACV and in other low-molecular-weight disulfide containing compounds and proteins. The disulfide reductase comprises two protein components, a 70-kDa reductase consisting of two identical subunits, and a 12-kDa heat-stable protein reductant. The structural and functional properties of the disulfide reductase resemble those of the thioredoxin class of oxidoreductases. When the disulfide reductase system is coupled with IPNS, it quantitatively converts bis-ACV to isopenicillin N. These findings suggest that the disulfide reductase may play a role in the biosynthesis of penicillins and cephalosporins in streptomycetes. We also show here that S. clavuligerus lacks glutathione reductase and have previously reported that Streptomyces species do not contain glutathione. This disulfide reductase may therefore be important in determining the thiol-disulfide redox balance in streptomycetes.

This article has been cited by other articles:

• Thon, M., Al-Abdallah, Q., Hortschansky, P., Brakhage, A. A. (2007). The Thioredoxin System of the Filamentous Fungus Aspergillus nidulans: IMPACT ON DEVELOPMENT AND OXIDATIVE STRESS RESPONSE. J. Biol. Chem. 282: 27259-27269 [Abstract] [Full Text]  
• Uziel, O., Borovok, I., Schreiber, R., Cohen, G., Aharonowitz, Y. (2004). Transcriptional Regulation of the Staphylococcus aureus Thioredoxin and Thioredoxin Reductase Genes in Response to Oxygen and Disulfide Stress. J. Bacteriol. 186: 326-334 [Abstract] [Full Text]  
• Borovok, I., Kreisberg-Zakarin, R., Yanko, M., Schreiber, R., Myslovati, M., Aslund, F., Holmgren, A., Cohen, G., Aharonowitz, Y. (2002). Streptomyces spp. contain class Ia and class II ribonucleotide reductases: expression analysis of the genes in vegetative growth. Microbiology 148: 391-404 [Abstract] [Full Text]  
• Brakhage, A. A. (1998). Molecular Regulation of beta -Lactam Biosynthesis in Filamentous Fungi. Microbiol. Mol. Biol. Rev. 62: 547-585 [Abstract] [Full Text]