Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0204, USA.
J Am Chem Soc. 2010 Sep 15;132(36):12757-65. doi: 10.1021/ja105891a.
Saliniketals A and B are unusual polyketides from the marine actinomycete Salinispora arenicola that inhibit ornithine decarboxylase induction. The structural similarities between the saliniketals and the ansa chain of the potent rifamycin antibiotics, which co-occur in the fermentation broth, suggest a common origin between the two compound classes. Using PCR-directed mutagenesis, chemical complementation studies, and stable isotope feeding experiments, we showed that the saliniketals are byproducts of the rifamycin biosynthetic pathway diverging at the stage of 34a-deoxyrifamycin W. Our results suggest that a single enzyme, the cytochrome P450 monooxygenase encoded by sare1259, catalyzes multiple oxidative rearrangement reactions on 34a-deoxyrifamyin W to yield both the saliniketal and rifamycin structural classes.
沙利奈克他 A 和 B 是海洋放线菌沙利氏菌中不寻常的聚酮类化合物，能抑制鸟氨酸脱羧酶的诱导。沙利奈克他类化合物与强效利福霉素抗生素ansa 链的结构相似，两者共同存在于发酵液中，这表明这两种化合物类具有共同的起源。通过 PCR 定向诱变、化学互补研究和稳定同位素喂养实验，我们表明沙利奈克他类化合物是 rifamycin 生物合成途径在 34a-去氧 rifamycin W 阶段分叉的副产物。我们的结果表明，单个酶，即 sare1259 编码的细胞色素 P450 单加氧酶，在 34a-去氧 rifamycin W 上催化多种氧化重排反应，生成沙利奈克他类化合物和利福霉素类化合物。
