Department of Biomolecular Mechanisms, Max-Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany.
Biochem Soc Trans. 2010 Aug;38(4):934-9. doi: 10.1042/BST0380934.
The cytochromes P450 (P450s) are a superfamily of oxidative haemoproteins that are capable of catalysing a vast range of oxidative transformations, including the oxidation of unactivated alkanes, often with high stereo- and regio-selectivity. Fatty acid hydroxylation by P450s is widespread across both bacteria and higher organisms, with the sites of oxidation and specificity of oxidation varying from system to system. Several key examples are discussed in the present article, with the focus on P450(BioI) (CYP107H1), a biosynthetic P450 found in the biotin operon of Bacillus subtilis. The biosynthetic function of P450(BioI) is the formation of pimelic acid, a biotin precursor, via a multiple-step oxidative cleavage of long-chain fatty acids. P450(BioI) is a member of an important subgroup of P450s that accept their substrates not free in solution, but rather presented by a separate carrier protein. Structural characterization of the P450(BioI)-ACP (acyl-carrier protein) complex has recently been performed, which has revealed the basis for the oxidation of the centre of the fatty acid chain. The P450(BioI)-ACP structure is the first such P450-carrier protein complex to be characterized structurally, with important implications for other biosynthetically intriguing P450-carrier protein complexes.
细胞色素 P450（P450s）是一类超家族氧化血红素蛋白，能够催化广泛的氧化转化，包括未激活烷烃的氧化，通常具有高立体和区域选择性。脂肪酸的羟化作用在细菌和高等生物中都很普遍，氧化部位和氧化特异性因系统而异。本文讨论了几个关键例子，重点介绍了枯草芽孢杆菌生物素操纵子中的生物合成 P450（P450（BioI）（CYP107H1）。P450（BioI）的生物合成功能是通过长链脂肪酸的多步氧化裂解形成生物素前体——壬二酸。P450（BioI）是一类重要的 P450 亚群的成员，它们接受的底物不是游离在溶液中的，而是由单独的载体蛋白提供。最近对 P450（BioI）-ACP（酰基载体蛋白）复合物进行了结构表征，揭示了脂肪酸链中心氧化的基础。P450（BioI）-ACP 结构是第一个被结构表征的这样的 P450-载体蛋白复合物，对其他具有生物合成吸引力的 P450-载体蛋白复合物具有重要意义。
