Escobedo-Hinojosa Wendy Itzel, Vences-Guzmán Miguel Ángel, Schubotz Florence, Sandoval-Calderón Mario, Summons Roger E, López-Lara Isabel María, Geiger Otto, Sohlenkamp Christian
From the Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos CP62210, Mexico and.
the Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02144.
J Biol Chem. 2015 Jun 12;290(24):15102-11. doi: 10.1074/jbc.M115.639575. Epub 2015 Apr 29.
Ornithine lipids (OLs) are phosphorus-free membrane lipids widespread in bacteria but absent from archaea and eukaryotes. In addition to the unmodified OLs, a variety of OL derivatives hydroxylated in different structural positions has been reported. Recently, methylated derivatives of OLs were described in several planctomycetes isolated from a peat bog in Northern Russia, although the gene/enzyme responsible for the N-methylation of OL remained obscure. Here we identify and characterize the OL N-methyltransferase OlsG (Sinac_1600) from the planctomycete Singulisphaera acidiphila. When OlsG is co-expressed with the OL synthase OlsF in Escherichia coli, methylated OL derivatives are formed. An in vitro characterization shows that OlsG is responsible for the 3-fold methylation of the terminal δ-nitrogen of OL. Methylation is dependent on the presence of the detergent Triton X-100 and the methyldonor S-adenosylmethionine.
鸟氨酸脂（OLs）是一种不含磷的膜脂，广泛存在于细菌中，而古细菌和真核生物中则没有。除了未修饰的OLs，还报道了多种在不同结构位置羟基化的OL衍生物。最近，在从俄罗斯北部泥炭沼泽分离出的几种浮霉菌中描述了OL的甲基化衍生物，尽管负责OL N-甲基化的基因/酶仍不清楚。在这里，我们从嗜酸奇异球囊菌中鉴定并表征了OL N-甲基转移酶OlsG（Sinac_1600）。当OlsG与OL合酶OlsF在大肠杆菌中共表达时，会形成甲基化的OL衍生物。体外表征表明，OlsG负责OL末端δ-氮的3倍甲基化。甲基化依赖于去污剂Triton X-1００和甲基供体S-腺苷甲硫氨酸的存在。
