fa بیان کپسول در باکتری اشرشیاکلی نیازمند پروتئین KfiB است: یک مطالعه مبتنی بر آنالیز ساختار و عملکرد <p align="left"><b><font face="TimesNewRoman,Bold" size="3">Abstract</font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">Background and objectives: </font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">important virulence factor for many invasive bacterial pathogens of humans.</font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">Escherichia coli offer a model system to study the mechanisms by which</font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">capsular polysaccharides are synthesized and exported onto the cell surface of</font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">bacteria. Biosynthesis of the E</font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">consists of the repeat structure -4) GlcA- (1, 4)-GlcNAc- (1-, requires the</font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">KfiA, KfiB, KfiC, and KfiD proteins. Until now , the role of all proteins</font></b></p> <p align="left"><b><font face="TimesNewRoman,Bold" size="3">except KfiB have been kown.</font></b></p> <b><font face="TimesNewRoman" size="3">Capsular polysaccharide expression is an</font><i><font face="TimesNewRoman,Italic" size="3">. coli </font><font face="TimesNewRoman" size="3">K5 capsular polysaccharide, which</font></i></b> <p align="left"><b><i><b><font face="TimesNewRoman,Bold" size="3">Material and Methods</font></b></i></b></p> <p align="left"><b><i><b><font face="TimesNewRoman,Bold" size="3">(pMA1) and several derivatives of KfiB expression construct (pMA2-6) were</font></b></i></b></p> <p align="left"><b><i><b><font face="TimesNewRoman,Bold" size="3">made with a 6Xhis-tag at the N-terminus. The presence of the hexa histidin tag</font></b></i></b></p> <p align="left"><b><i><b><font face="TimesNewRoman,Bold" size="3">facilitated purification of the KfiB protein using Ni</font></b></i></b></p> <b><i><b><font face="TimesNewRoman" size="3">: To study the role of the KfiB protein, a full-length</font><font face="TimesNewRoman" size="1">2+</font><font face="TimesNewRoman" size="3">-NTA chromatography.</font></b></i></b> <p align="left"><b><i><b><b><font face="TimesNewRoman,Bold" size="3">Results:</font></b></b></i></b></p> <p align="left"><b><i><b><b><font face="TimesNewRoman,Bold" size="3">pPC6::23 and restore capsule production. Successful complementation by</font></b></b></i></b></p> <p align="left"><b><i><b><b><font face="TimesNewRoman,Bold" size="3">pMA1, showed that the fused hexa-histidine tag did not interrupt the function</font></b></b></i></b></p> <p align="left"><b><i><b><b><font face="TimesNewRoman,Bold" size="3">of KfiB and that the full-length KfiB is required for complementation.</font></b></b></i></b></p> <b><i><b><b><font face="TimesNewRoman" size="3">All plasmids except pMA1 failed to complement the mutation in</font></b></b></i></b> <p align="left"><b><i><b><b><font color="#ffffff" face="TimesNewRoman" size="3">Roberts, I.S.</font></b></b></i></b></p> <p align="left"><b><i><b><b><b><font face="TimesNewRoman,Bold" size="3">Conclusion:</font></b></b></b></i></b></p> <p align="left"><b><i><b><b><b><font face="TimesNewRoman,Bold" size="3">cytoplasmic membrane.</font></b></b></b></i></b></p> <b><i><b><b><b><font face="TimesNewRoman" size="3">Localization studies revealed that KfiB is associated with the</font></b></b></b></i></b> <p><b><i><b><b><b><b><font face="TimesNewRoman,Bold" size="3">Key words: </font></b></b></b></b></i></b></p> <b><i><b><b><b><b><font face="TimesNewRoman" size="3">Escherichia coli, Capsular polysaccharide, KfiB, K5</font></b></b></b></b></i></b> Key words: Escherichia coli, Capsular polysaccharide, KfiB, K5 0 0 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1-54&slc_lang=fa&sid=1 m Pourhossein معراج پورحسین pourhossein@med.mui.ac.ir 100319475328460013071 100319475328460013071 Yes Assistant Professor of دانشجوی پزشکی ، دانشگاه علوم پزشکی اصفهان I.S Roberts ایان اس روبرتس 100319475328460013072 100319475328460013072 No دانشگاه منچستر