Amycolatopsis mediterranei U32

Amycolatopsis mediterranei (strain U-32) is a Gram-positive bacterium used for industry-scale production of rifamycin, which plays a vital role in antimycobacterial therapy. As the first sequenced genome of the genus Amycolatopsis, the chromosome of A.mediterranei comprising 10 236 715 base pairs, is one of the largest prokaryotic genomes ever sequenced so far. Although the predicted 9 228 protein-coding genes in the A. mediterranei genome shares the greatest number of orthologs with those of S. erythraea, it is unexpectedly followed by Streptomyces coelicolor rather than N. farcinica, indicating the distinct metabolic characteristics evolves via adaptation to diverse ecological niches. Besides a core region analogous to that common in streptomycetes, a novel 'quasi-core' with typical core characteristics is defined within the non-core region, where 21 out of the total 26 gene clusters for secondary metabolite production are located. The rifamycin biosynthesis gene cluster located in the core encodes a cytochrome P450 enzyme essential for the conversion of rifamycin SV to B, revealed by comparing to the highly homologous cluster of the rifamycin B-producing strain S699 and further confirmed by genetic complementation. The genomic information of A. mediterranei demonstrates a metabolic network orchestrated not only for extensive utilization of various carbon sources and inorganic nitrogen compounds but also for effective funneling of metabolic intermediates into the secondary antibiotic synthesis process under the control of a seemingly complex regulatory mechanism. (adapted from PMID: 20567260). (EBI Integr8)