Geiger Otto, López-Lara Isabel M, Sohlenkamp Christian
Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico.
Biochim Biophys Acta. 2013 Mar;1831(3):503-13. doi: 10.1016/j.bbalip.2012.08.009. Epub 2012 Aug 19.
Phosphatidylcholine (PC) is the major membrane-forming phospholipid in eukaryotes and is estimated to be present in about 15% of the domain Bacteria. Usually, PC can be synthesized in bacteria by either of two pathways, the phospholipid N-methylation (Pmt) pathway or the phosphatidylcholine synthase (Pcs) pathway. The three subsequent enzymatic methylations of phosphatidylethanolamine are performed by a single phospholipid N-methyltransferase in some bacteria whereas other bacteria possess multiple phospholipid N-methyltransferases each one performing one or several distinct methylation steps. Phosphatidylcholine synthase condenses choline directly with CDP-diacylglycerol to form CMP and PC. Like in eukaryotes, bacterial PC also functions as a biosynthetic intermediate during the formation of other biomolecules such as choline, diacylglycerol, or diacylglycerol-based phosphorus-free membrane lipids. Bacterial PC may serve as a specific recognition molecule but it affects the physicochemical properties of bacterial membranes as well. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism.
磷脂酰胆碱（PC）是真核生物中主要的膜形成磷脂，据估计在约15%的细菌域中存在。通常，PC可通过磷脂N-甲基化（Pmt）途径或磷脂酰胆碱合酶（Pcs）途径这两条途径之一在细菌中合成。在一些细菌中，磷脂酰乙醇胺随后的三次酶促甲基化由单一的磷脂N-甲基转移酶进行，而其他细菌则拥有多种磷脂N-甲基转移酶，每种酶执行一个或几个不同的甲基化步骤。磷脂酰胆碱合酶直接将胆碱与CDP-二酰甘油缩合形成CMP和PC。与真核生物一样，细菌PC在其他生物分子如胆碱、二酰甘油或基于二酰甘油的无磷膜脂形成过程中也作为生物合成中间体发挥作用。细菌PC可能作为一种特异性识别分子，但它也会影响细菌膜的物理化学性质。本文是名为“磷脂与磷脂代谢”的特刊的一部分。
