Commonality and biosynthesis of the O-methyl phosphoramidate capsule modification in Campylobacter jejuni
Commonality and biosynthesis of the O-methyl phosphoramidate capsule modification in Campylobacter jejuni
复制标题
DOI：
10.1074/jbc.m704413200
复制
发表时间：
2007-09-28
影响因子：
4.8
通讯作者：
Szymanski, Christine M.
中科院分区：
文献类型：
--
作者：
McNally, David J.;Lamoureux, Marc P.;Szymanski, Christine M.
在这项研究中，我们研究了空肠弯曲菌荚膜多糖（CPS）上发现的O-甲基氨基磷酸酯（MeOPN）基团的共性和生物合成。使用高分辨率魔角旋转NMR光谱作为快速、高通量手段来检查多种分离物，分析定殖鸡的盲肠内容物，并筛选CPS突变体文库中MeOPN的存在。68%的C.发现空肠菌株表达MeOPN，在来自肠炎、格林巴利和米勒-费希尔综合征患者的分离株中具有高流行率。相比之下，对于所检查的任何结肠弯曲杆菌菌株均未观察到MeOPN。在C.从定殖的鸡的盲肠内容物中回收的空肠，证明该修饰由栖息在禽胃肠道中的细菌表达。In C. jejuni 11168 H中，cj 1415-cj 1418簇显示参与MeOPN的生物合成。来自该菌株的CPS的遗传互补研究和NMR/质谱分析也揭示了cj 1421和cj 1422编码MeOPN转移酶。Cj 1421将MeOPN添加到β-D-GalfNAc残基的C-3，而Cj 1422将MeOPN转移到D-甘油-α-L-吡喃庚葡糖的C-4。发现由11168 H菌株产生的CPS被可变的MeOPN、甲基、乙醇胺和N-甘油基团广泛修饰。这些发现确立了MeOPN作为C.空肠的MeOPN生物合成途径，并为旨在详细阐明MeOPN生物合成途径的未来研究奠定基础。
In this study we investigated the commonality and biosynthesis of the O-methyl phosphoramidate (MeOPN) group found on the capsular polysaccharide (CPS) of Campylobacter jejuni. High resolution magic angle spinning NMR spectroscopy was used as a rapid, high throughput means to examine multiple isolates, analyze the cecal contents of colonized chickens, and screen a library of CPS mutants for the presence of MeOPN. Sixty eight percent of C. jejuni strains were found to express the MeOPN with a high prevalence among isolates from enteritis, Guillain Barre , and Miller-Fisher syndrome patients. In contrast, MeOPN was not observed for any of the Campylobacter coli strains examined. The MeOPN was detected on C. jejuni retrieved from cecal contents of colonized chickens demonstrating that the modification is expressed by bacteria inhabiting the avian gastrointestinal tract. In C. jejuni 11168H, the cj1415-cj1418 cluster was shown to be involved in the biosynthesis of MeOPN. Genetic complementation studies and NMR/ mass spectrometric analyses of CPS from this strain also revealed that cj1421 and cj1422 encode MeOPN transferases. Cj1421 adds the MeOPN to C-3 of the beta-D-GalfNAc residue, whereas Cj1422 transfers the MeOPN to C-4 of D-glycero-alpha-L-glucoheptopyranose. CPS produced by the 11168H strain was found to be extensively modified with variable MeOPN, methyl, ethanolamine, and N-glycerol groups. These findings establish the importance of the MeOPN as a diagnostic marker and therapeutic target for C. jejuni and set the groundwork for future studies aimed at the detailed elucidation of the MeOPN biosynthetic pathway.