Cholesterol-dependent cytolysins(CDC)are pore forming toxins.A prototype of the CDC family members is perfringolysin O(PFO),which directly binds to the cell membrane enriched in cholesterol,causing cell lysis.However,...Cholesterol-dependent cytolysins(CDC)are pore forming toxins.A prototype of the CDC family members is perfringolysin O(PFO),which directly binds to the cell membrane enriched in cholesterol,causing cell lysis.However,an exception of this general observation is intermedilysin(ILY)of Streptococcus intermedius,which requires human CD59 as a receptor in addition to cholesterol for its hemolytic activity.A possible explanation of this functional difference is the conformational variation between the C-terminal domains of the two toxins,particularly in the highly conserved undecapeptide termed tryptophan rich motif.Here,we present the crystal structure of suilysin,a CDC toxin from the infectious swine pathogen Streptococcus suis.Like PFO,suilysin does not require a host receptor for hemolytic activity;yet the crystal structure of suilysin exhibits a similar conformation in the tryptophan rich motif to ILY.This observation suggests that the current view of the structure-function relationship between CDC proteins and membrane association is far from complete.展开更多
猪链球菌(Streptococcus suis)是一种重要的人畜共患病原菌,其中猪链球菌2型(Streptococcus suis type 2,SS2)致病性最强、发病率最高,SS2患病猪只传染给人,可导致败血症、心内膜炎、关节炎及脑膜炎等症状。关于其毒力因子的挖掘与功能...猪链球菌(Streptococcus suis)是一种重要的人畜共患病原菌,其中猪链球菌2型(Streptococcus suis type 2,SS2)致病性最强、发病率最高,SS2患病猪只传染给人,可导致败血症、心内膜炎、关节炎及脑膜炎等症状。关于其毒力因子的挖掘与功能探索一直是猪链球菌致病机理研究的重要方向。溶血素(Sly)作为猪链球菌2型分泌性毒力因子,一直被视为是SS2的毒力标志因子之一,在细菌感染与致病过程中扮演重要作用。本文阐述了猪链球菌2型溶血素因子的溶血特性与分子结构,并重点论述Sly因子在介导SS2的黏附与侵袭、细菌繁殖与免疫逃避、突破血脑屏障与诱导脑膜炎等感染生物学过程中的作用。以期为推进猪链球菌基础研究及其他链球菌溶血素因子的机制探索提供参考。展开更多
根据猪链球菌2型(strep tococcus su is type 2)溶血素基因(sly)设计和合成了一对可扩增其完整阅读框的引物,对HA 9801等6株猪链球菌2型江苏分离株、1株德国分离株SS2-D及猪链球菌C群参考株ATCC 35246的核酸进行PCR扩增,结果显示HA 9801...根据猪链球菌2型(strep tococcus su is type 2)溶血素基因(sly)设计和合成了一对可扩增其完整阅读框的引物,对HA 9801等6株猪链球菌2型江苏分离株、1株德国分离株SS2-D及猪链球菌C群参考株ATCC 35246的核酸进行PCR扩增,结果显示HA 9801等6株江苏分离株及德国株SS2呈阳性,ATCC 35246呈阴性。HA 9801株PCR产物纯化后测序,序列分析结果表明该DNA片段与猪链球菌2型1933株的sly基因同源性为99%。展开更多
基金This work was supported by the National Programs for High Technology Research and Development Program(863 Program)No.2006AA02A322to X.L.,the CAS grant KSCX2-YW-05 to Z.R,the Project of Protein Studies(CAS)grant 2006CB10903National Basic Research Program(973 Program)No.2007CB914304.
文摘Cholesterol-dependent cytolysins(CDC)are pore forming toxins.A prototype of the CDC family members is perfringolysin O(PFO),which directly binds to the cell membrane enriched in cholesterol,causing cell lysis.However,an exception of this general observation is intermedilysin(ILY)of Streptococcus intermedius,which requires human CD59 as a receptor in addition to cholesterol for its hemolytic activity.A possible explanation of this functional difference is the conformational variation between the C-terminal domains of the two toxins,particularly in the highly conserved undecapeptide termed tryptophan rich motif.Here,we present the crystal structure of suilysin,a CDC toxin from the infectious swine pathogen Streptococcus suis.Like PFO,suilysin does not require a host receptor for hemolytic activity;yet the crystal structure of suilysin exhibits a similar conformation in the tryptophan rich motif to ILY.This observation suggests that the current view of the structure-function relationship between CDC proteins and membrane association is far from complete.
文摘猪链球菌(Streptococcus suis)是一种重要的人畜共患病原菌,其中猪链球菌2型(Streptococcus suis type 2,SS2)致病性最强、发病率最高,SS2患病猪只传染给人,可导致败血症、心内膜炎、关节炎及脑膜炎等症状。关于其毒力因子的挖掘与功能探索一直是猪链球菌致病机理研究的重要方向。溶血素(Sly)作为猪链球菌2型分泌性毒力因子,一直被视为是SS2的毒力标志因子之一,在细菌感染与致病过程中扮演重要作用。本文阐述了猪链球菌2型溶血素因子的溶血特性与分子结构,并重点论述Sly因子在介导SS2的黏附与侵袭、细菌繁殖与免疫逃避、突破血脑屏障与诱导脑膜炎等感染生物学过程中的作用。以期为推进猪链球菌基础研究及其他链球菌溶血素因子的机制探索提供参考。
文摘根据猪链球菌2型(strep tococcus su is type 2)溶血素基因(sly)设计和合成了一对可扩增其完整阅读框的引物,对HA 9801等6株猪链球菌2型江苏分离株、1株德国分离株SS2-D及猪链球菌C群参考株ATCC 35246的核酸进行PCR扩增,结果显示HA 9801等6株江苏分离株及德国株SS2呈阳性,ATCC 35246呈阴性。HA 9801株PCR产物纯化后测序,序列分析结果表明该DNA片段与猪链球菌2型1933株的sly基因同源性为99%。
