细菌的磷酸转移酶系统.ppt

细菌的磷酸转移酶系统BacterialPhosphotransferaseSystemLeading：Bacteriaarethriftycells.Theyoftenliveininhospitableenvironments,andmanyliveinplaceswithnooxygen,sotheiroptionsforgeneratingenergyarelimited.So,bacteriahavedevelopedmanycleverwaysoflivingoffofwhateverisavailable,andexploitingtheseresourcestotheirbestadvantage.Thebacterialphosphotransferasesystem,oftenabbreviatedasPTS,isaperfectexampleofboththeopportunisticnatureofbacteriallife,andtheirthriftyuseofresources.注释：细菌是种节俭的细胞生物体。他们通常都在恶劣的环境当中生存，甚至许多生存在没有氧气的地方，所以他们产生能量的方式选择非常有限。因此细菌自身培养了许多巧妙的方法以适应接触的任何环境，以及开发这些资源于自身以最好的利用。细菌的磷酸转移酶系统，通常缩写为PTS，无论是对细菌生活的多机会自然环境，还是他们节俭使用的资源，都是一个完美的例子。细菌中糖的磷酸转移酶功能发现In1964,Kundig,GhoshandRosemanreportedthediscoveryofthePEP:sugarphosphotransferasesystem(PTS).Thirtyyearslater,wefindthatthePTSfunctionsnotonlyasasugar-phosphorylatingsystem,butalsoasacomplexproteinkinase（复合蛋白激酶）systemthatregulates（调节）awidevarietyofmetabolic（新陈代谢的）processesandcontrolstheexpressionofnumerous（大量）genes.Asaresultofrecentoperon-andgenome-sequencingprojects,novel新的PTSprotein-encoding编码geneshavebeendiscovered,mostofwhichhaveyettobefunctionallydefined.Someofthemappeartobeinvolvedincellular细胞的processesdistinctfromthoserecognizedpreviously先前的.FundamentalaspectsofpastandcurrentPTSresearcharebrieflyreviewed,andrecentadvances增长areintegrated整合intoconceptualpicturesthatprovideguidesforfutureresearch.HowPhosphotransferaseSystem-RelatedProteinPhosphorylationRegulatesCarbohydrateMetabolism（糖类新陈代谢系统）inBacteria蛋白的磷酸化及去磷酸化状态在分解物代谢阻遏中起关键作用。PTS系统是运载体家族中的转位分子，在原核生和古细菌中广泛存在。大肠杆菌主要通过PEP—sugarPTS以集团转移方式进行葡萄糖的摄取，PTS包括EI，HPr，EII。前两者为胞质可溶型蛋白，无底物识别特异性。分别由pstI，pstH操纵子编码，后者多为蛋白复合体，对碳水化合物具有识别特异性,可特异性识别和转运底物分子，E.coli编码约20种EⅡs，涉及20多种不同碳化物磷酸化转运。磷酸转移酶系统蛋白-蛋白复合体的三维结构01040203Hpr:histidine-containingphosphocarrierpro