The marine bacterium Pseudoalteromonas tunicata produces the bipyrrole antibiotic tambjamine YP1. This natural product is built from common amino acid and fatty acid building blocks in a biosynthetic pathway that is encoded in the tam operon which contains 19 genes. The exact role that each of these Tam proteins plays in tambjamine biosynthesis is not known. Here, we provide evidence that TamA initiates the synthesis and controls the chain length of the essential tambjamine fatty amine tail. Sequence analysis suggests the unusual TamA is comprised of an N-terminal adenylation (ANL) domain fused to a C-terminal acyl carrier protein (ACP). Mass spectrometry analysis of recombinant TamA revealed the surprising presence of bound C11 and C12 acyl-adenylate intermediates. Acylation of the ACP domain was observed upon attachment of the phosphopantetheine (4′-PP) arm to the ACP. We also show that TamA can transfer fatty acids ranging in chain length from C6–C13 to an isolated ACP domain. Thus TamA bridges the gap between primary and secondary metabolism by linking fatty acid and pyrrole biosynthetic pathways.

中文翻译：

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碳链选择性腺苷酸化酶TamA：脂肪酸与吡咯天然产物生物合成之间的缺失环节†

海洋细菌Pseudoalteromonas tunicata产生联吡咯抗生素tambjamine YP1。这种天然产物是由tam编码的生物合成途径中的常见氨基酸和脂肪酸组成的操纵子包含19个基因。这些Tam蛋白中的每一种在他巴明的生物合成中所起的确切作用尚不清楚。在这里，我们提供证据表明TamA启动合成并控制必需的tambjamine脂肪胺尾巴的链长。序列分析表明，异常的TamA由与C末端酰基载体蛋白（ACP）融合的N末端腺苷酸化（ANL）域组成。重组TamA的质谱分析表明，结合的C11和C12酰基-腺苷酸中间体出人意料地存在。在磷酸泛肽（4'-PP）臂连接到ACP时，观察到ACP域的酰化。我们还显示，TamA可以将链长范围从C6–C13的脂肪酸转移到分离的ACP结构域。