Properties of the glucose-6-phosphate transporter from Chlamydia pneumoniae (HPTcp) and the glucose-6-phosphate sensor from Escherichia coli (UhpC).
Properties of the glucose-6-phosphate transporter from Chlamydia pneumoniae (HPTcp) and the glucose-6-phosphate sensor from Escherichia coli (UhpC).
复制标题
肺炎衣原体 (HPTcp) 的葡萄糖-6-磷酸转运蛋白和大肠杆菌 (UhpC) 的葡萄糖-6-磷酸传感器的特性。
DOI：
10.1128/jb.184.8.2108-2115.2002
复制
发表时间：
2002
影响因子：
3.2
通讯作者：
Neuhaus,HEkkehard
中科院分区：
文献类型：
--
作者：
Schwöppe,Christian;Winkler,HerbertH;Neuhaus,HEkkehard
The amino acid sequence of the proposed glucose-6-phosphate (Glc6P) transporter fromChlamydia pneumoniae(HPTcp; hexose phosphate transporter [Chlamydia pneumoniae]) exhibits a higher degree of similarity to theEscherichia coliGlc6P sensor (UhpC) than to theE. coliGlc6P transporter (UhpT). Overexpression of His-UhpC in a UhpT-deficientE. colistrain revealed that the sensor protein is also able to transport Glc6P and exhibits an apparentKm(Glc6P)of 25 μM, whereas His-HPTcp exhibits an apparentKm(Glc6P)of 98 μM. His-HPTcp showed a four-times-lower specific activity than His-UhpT but a 56-times-higher specific activity than His-UhpC. Like His-UhpT and His-UhpC, the carrier His-HPTcp performs a sugar-phosphate/inorganic-phosphate antiporter mode of transport. Surprisingly, while physiological concentrations of inorganic phosphate competitively inhibited transport mediated by theE. coliproteins His-UhpT and His-UhpC, transport mediated by His-HPTcp was not inhibited. Interestingly, C3-organophosphates stimulated His-HPTcp activity but not His-UhpT- or His-UhpC-catalyzed Glc6P transport. In contrast to His-UhpC, the His-HPTcp protein does not act as a Glc6P sensor in theuhpregulon.
