Molecular Characterization of Type-Specific Capsular Polysaccharide Biosynthesis Genes of Streptococcus agalactiae Type Ia
Molecular Characterization of Type-Specific Capsular Polysaccharide Biosynthesis Genes of Streptococcus agalactiae Type Ia
复制标题
Ia 型无乳链球菌特异性荚膜多糖生物合成基因的分子特征
作者：
Shin Yamamoto;K. Miyake;Y. Koike;Masaki Watanabe;Y. Machida;M. Ohta;S. Iijima
无乳链球菌（Streptococcus agalactiae）Ia型是一种B族链球菌，其荚膜多糖是由五糖重复单元4）-[α-d-NeupNAc-（2→3）-β-d-Galp-（1→4）-β-d-GlcpNAc-（1→3）]-β-d-Galp-（1→4）-β-d-Glcp-（1.在这里，克隆，测序和转录的Ia型特异性荚膜多糖合成（CPS）基因和这些基因产物的功能分析。克隆了一个含有18个完整开放阅读框（ORF）的26-kb DNA片段。这些ORF被命名为cpsIaA至cpsIaL、neu（神经氨酸合成基因）A至D、orf 1和ung（尿嘧啶DNA糖基化酶）。将S. Ia型无乳链球菌与S.无乳链球菌III型和无乳链球菌S.肺炎血清型14。与S. pneumoniae血清型14中，该操纵子的转录可能从cpsIaA、cpsIaE和orf 1开始，因为在这些基因前面发现了推定的启动子序列。北方杂交，逆转录-PCR和引物延伸分析支持这一假设。DNA序列分析表明，该操纵子的3′端有两个转录终止子（forf 1和ung的下游）。利用在大肠杆菌JM 109中表达的基因产物，通过糖基转移酶试验检测了CpsIaE、CpsIaG、CpsIaJ和CpsIaJ的功能。无乳型Iacps基因片段酶活性分析表明，cpsIaE、cpsIaG、cpsIaJ和cpsIaJ的基因产物分别是葡萄糖基转移酶、β-1，4-半乳糖基转移酶、β-1，3-N-乙酰氨基葡萄糖基转移酶和β-1，4-半乳糖基转移酶。
ABSTRACT The type-specific capsular polysaccharide (CP) of a group B streptococcus, Streptococcus agalactiae type Ia, is a high-molecular-weight polymer consisting of the pentasaccharide repeating unit 4)-[α-d-NeupNAc-(2→3)-β-d-Galp-(1→4)-β-d-GlcpNAc-(1→3)]-β-d-Galp-(1→4)-β-d-Glcp-(1. Here, cloning, sequencing, and transcription of the type Ia-specific capsular polysaccharide synthesis (cps) genes and functional analysis of these gene products are described. A 26-kb DNA fragment containing 18 complete open reading frames (ORFs) was cloned. These ORFs were designated cpsIaA tocpsIaL, neu (neuraminic acid synthesis gene)A to D, orf1 and ung(uracil DNA glycosylase). The cps gene products of S. agalactiae type Ia were homologous to proteins involved in CP synthesis of S. agalactiae type III and S. pneumoniae serotype 14. Unlike the cps gene cluster of S. pneumoniae serotype 14, transcription of this operon may start from cpsIaA, cpsIaE, andorf1 because putative promoter sequences were found in front of these genes. Northern hybridization, reverse transcription-PCR, and primer extension analyses supported this hypothesis. DNA sequence analysis showed that there were two transcriptional terminators in the 3′ end of this operon (downstream oforf1 and ung). The functions of CpsIaE, CpsIaG, CpsIaI, and CpsIaJ were examined by glycosyltransferase assay by using the gene products expressed in Escherichia coli JM109 harboring plasmids containing various S. agalactiae type Iacps gene fragments. Enzyme assays suggested that the gene products of cpsIaE, cpsIaG, cpsIaI, and cpsIaJ are putative glucosyltransferase, β-1,4-galactosyltransferase, β-1,3-N-acetylglucosaminyltransferase, and β-1,4-galactosyltransferase, respectively.
III B 型链球菌荚膜多糖寡糖重复单元的结构和免疫化学。
DOI：
--
发表时间：
1987
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Wessels,MR;Pozsgay,V;Kasper,DL;Jennings,HJ
通讯作者：
Jennings,HJ
IV 型 B 族链球菌荚膜多糖的分离和表征。
影响因子：
3.1
作者：
Wessels,MR;Benedí,WJ;Jennings,HJ;Michon,F;DiFabio,JL;Kasper,DL
通讯作者：
Kasper,DL