Streptomyces clavuligerus proteins

Homeologous recombination (recombination between partially homologous sequences) was used to produce novel, functional expandase enzymes in vivo) which are hybrids of the S. clavuligerus and N. lactamdurans proteins. DNA sequencing of hybrids obtained in E. coli showed that recombination had occurred at several locations displaying conserved sequences as short as 2 bp. Hybrid genes obtained in a Streptomyces background produced expandases with altered activity on penicillin G, as confirmed by HPLC analysis. 

S. clavuligerus produces several antibiotics, including the P-lactams cephamycin C and clavulanic acid, a P-lactamase inhibitor. A SARP type protein, CcaR, is required for the biosynthesis of cephamycin C and clavulanic acid (Perez-Llarena et al. 1997). The clusters of genes for both compounds are located side by side in three different Streptomyces species (Ward and Hodgson 1993) and the ccaR gene is located in the cephamycin gene cluster. 

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