19F型肺炎链球菌荚膜多糖生物合成基因座的特征分析

Characterization of the capsular polysaccharide biosynthesis locus of Streptococcus pneumoniae type 19F.

作者信息

Paton J C, Morona J K, Morona R

机构信息

Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, S.A., Australia.

出版信息

Microb Drug Resist. 1997 Spring;3(1):89-99. doi: 10.1089/mdr.1997.3.89.

DOI:10.1089/mdr.1997.3.89

PMID:9109099

Abstract

We have used a combination of plasmid insertion/rescue and inverse Polymerase Chain Reaction (PCR) to clone the region of the Streptococcus pneumoniae type 19F chromosome encoding biosynthesis of type 19F capsular polysaccharide (cps19f), which was then subjected to sequence analysis. The cps19f locus is located in the S. pneumoniae chromosome between dexB and aliA, and consists of 15 open reading frames (ORFs), designated cps19fA to cps19fO, that appear to be arranged as a single transcriptional unit. Insertion-duplication mutants in 13 of the 15 ORFs have been constructed in a smooth type 19F strain, all of which resulted in a rough (unencapsulated) phenotype, confirming that the operon is essential for capsule production. Comparison with sequence databases has allowed us to propose functions for 12 of the cps19f gene products, and a biosynthetic pathway for type 19F capsular polysaccharide. Southern hybridization analysis indicated that cps19fA and cps19fB were the only cps genes found in all 16 S. pneumoniae serotypes/groups tested. The region from cps19fG to cps19fK was found only in members of serogroup 19, and within this cps19fI was unique to type 19F.

摘要

我们采用质粒插入/拯救与反向聚合酶链反应（PCR）相结合的方法，克隆了肺炎链球菌19F型染色体上编码19F型荚膜多糖（cps19f）生物合成的区域，随后对其进行了序列分析。cps19f基因座位于肺炎链球菌染色体上dexB和aliA之间，由15个开放阅读框（ORF）组成，命名为cps19fA至cps19fO，它们似乎排列成一个单一的转录单元。已在光滑型19F菌株中构建了15个ORF中的13个的插入重复突变体，所有这些突变体均导致粗糙（无荚膜）表型，证实该操纵子对于荚膜产生至关重要。与序列数据库的比较使我们能够推测出12种cps19f基因产物的功能，以及19F型荚膜多糖的生物合成途径。Southern杂交分析表明，cps19fA和cps19fB是在所有16种测试的肺炎链球菌血清型/组中发现的仅有的cps基因。从cps19fG到cps19fK的区域仅在19血清群的成员中发现，并且在该区域内，cps19fI是19F型所特有的。