Streptomyces clavuligerus, an industrially important producer of clavulanate as well as cephem antibiotics, also produces the N-acylated dithiolopyrrolone antibiotic holomycin, a reported inhibitor of RNA synthesis. The genome sequence of S. clavuligerus ATCC 27064 was examined for a potential biosynthetic gene cluster, assuming that holomycin arises from some derivative of an L-Cys-L-Cys dipep...

In the presence of S-adenosylmethionine, 2-oxoglutarate, Fe2+ and a reducing agent, cell-free extracts of Streptomyces clavuligerus convert cephalosporin C and 0carbamoyldeacetylcephalosporin C into 7a-methoxy derivatives. No synthesis of a 7a-methoxy derivative of deacetylcephalosporin C was detected in the system used, and the 7a-methoxy derivative of deacetoxycephalosporin C was produced onl...

BACKGROUND Some types of flavonoid intermediates seemed to be restricted to plants. Naringenin is a typical plant metabolite, that has never been reported to be produced in prokariotes. Naringenin is formed by the action of a chalcone synthase using as starter 4-coumaroyl-CoA, which in dicotyledonous plants derives from phenylalanine by the action of a phenylalanine ammonia lyase. RESULTS A c...

β-lactam antibiotics are among the most popular classes of antibacterial agents, whose mechanism of action consists on the inhibition of bacterial cell wall synthesis.1 The production of β-lactamase is the most important mechanism for bacterial resistance to β-lactam antibiotics.2 Secondary metabolites produced by bacteria exhibit potent biological activities and have been developed extensively...

CcaR is a positive-acting transcriptional regulator involved in cephamycin C and clavulanic acid biosynthesis in Streptomyces clavuligerus. Previous sequence analyses of the ccaR gene revealed two possible start codons, an ATG, and a GTG located in-frame 18 bp downstream of the ATG. To determine the true start codon, ccaR was expressed, either from the GTG or ATG codon, in Escherichia coli. A p...

Streptomyces clavuligerus produces at least five different clavam metabolites, including clavulanic acid and the methionine antimetabolite, alanylclavam. In vitro transposon mutagenesis was used to analyze a 13-kb region upstream of the known paralogue gene cluster. The paralogue cluster includes one group of clavulanic acid biosynthetic genes in S. clavuligerus. Twelve open reading frames (ORF...

A Streptomyces clavuligerus gene (designated pcbR) which is located immediately downstream from the gene encoding isopenicillin N synthase in the cephamycin gene cluster was characterized. Nucleotide sequence analysis and database searching of PcbR identified a significant similarity between PcbR and proteins belonging to the family of high-molecular-weight group B penicillin-binding proteins (...

Carboxyethylarginine synthase genes show complex cross regulation in 1 Streptomyces clavuligerus 2 Thomas Kwong, Kapil Tahlan, Cecilia L. Anders and Susan E. Jensen 3 Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9 Canada 4 5 6

Protoplasts of the wild type Streptomyces clavuligerus NRRL 3585 (ATCC 27064) were formed from spores cultures obtained in the lag, exponential and stationary growth phases by using 0.5% glycine in the culture medium. The protoplasts were obtained by treatment of the cells with lysozyme (EC-3.2.1.17) 40,000 U (1mg/ mL), in an osmotic solution for 90 min at 28oC. The frequency of regenerated pro...