Analysis of Campylobacter jejuni capsular loci reveals multiple mechanisms for the generation of structural diversity and the ability to form complex heptoses
Analysis of Campylobacter jejuni capsular loci reveals multiple mechanisms for the generation of structural diversity and the ability to form complex heptoses
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DOI：
10.1111/j.1365-2958.2004.04374.x
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发表时间：
2005-01-01
影响因子：
3.6
通讯作者：
Szymanski, CM
中科院分区：
文献类型：
--
作者：
Karlyshev, AV;Champion, OL;Szymanski, CM
我们最近证明空肠弯曲菌产生荚膜多糖（CPS），其是经典Penner血清分型系统将弯曲菌区分成>60组的主要抗原组分。虽然C.空肠血清型提示CPS的结构差异，这种差异的遗传机制尚不清楚。在这项研究中，我们测序生物合成的cps区域，大小从15到34 kb，从选定的C。HS：1、HS：19、HS：23、HS：36、HS：23/36和HS：41血清型的空肠菌株。HS：1，HS：19和HS：41菌株与测序菌株NCTC 11168（HS：2）的cps序列的比较，为多种结构变异机制提供了证据，包括通过水平转移，基因复制，缺失，融合和偶然基因变异引起的荚膜基因和整个簇的交换。相比之下，HS：23、HS：36和HS：23/36 cps序列高度保守。我们报告了81-176（HS：23/36）和G1（HS：1）的第一次详细结构分析，并完善了以前的HS：19，HS：23，HS：36和HS：41血清菌株的结构解释。对于第一次，我们证明的共性和功能的第二庚糖生物合成途径的弯曲杆菌CPS独立的脂寡糖（LOS）的生物合成途径，并确定一种新的庚糖基转移酶利用这种替代途径。此外，我们发现保留两个功能庚糖异构酶在弯曲杆菌和共享的磷酸酶的LOS和CPS庚糖生物合成。
We recently demonstrated that Campylobacter jejuni produces a capsular polysaccharide (CPS) that is the major antigenic component of the classical Penner serotyping system distinguishing Campylobacter into >60 groups. Although the wide variety of C. jejuni serotypes are suggestive of structural differences in CPS, the genetic mechanisms of such differences are unknown. In this study we sequenced biosynthetic cps regions, ranging in size from 15 to 34 kb, from selected C. jejuni strains of HS:1, HS:19, HS:23, HS:36, HS:23/36 and HS:41 serotypes. Comparison of the determined cps sequences of the HS:1, HS:19 and HS:41 strains with the sequenced strain, NCTC11168 (HS:2), provides evidence for multiple mechanisms of structural variation including exchange of capsular genes and entire clusters by horizontal transfer, gene duplication, deletion, fusion and contingency gene variation. In contrast, the HS:23, HS:36 and HS:23/36 cps sequences were highly conserved. We report the first detailed structural analysis of 81-176 (HS:23/36) and G1 (HS:1) and refine the previous structural interpretations of the HS:19, HS:23, HS:36 and HS:41 serostrains. For the first time, we demonstrate the commonality and function of a second heptose biosynthetic pathway for Campylobacter CPS independent of the pathway for lipooligosaccharide (LOS) biosynthesis and identify a novel heptosyltransferase utilized by this alternate pathway. Furthermore, we show the retention of two functional heptose isomerases in Campylobacter and the sharing of a phosphatase for both LOS and CPS heptose biosynthesis.