STRUCTURE OF THE REGULATORY COMPLEX OF ESCHERICHIA-COLI III(GLC) WITH GLYCEROL KINASE
STRUCTURE OF THE REGULATORY COMPLEX OF ESCHERICHIA-COLI III(GLC) WITH GLYCEROL KINASE
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DOI：
10.1126/science.8430315
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发表时间：
1993-01-29
期刊：
影响因子：
56.9
通讯作者：
REMINGTON, SJ
中科院分区：
文献类型：
--
作者：
HURLEY, JH;FABER, HR;REMINGTON, SJ
磷酸载体蛋白III（Glc）是细菌磷酸转移酶（PTS）系统的组成部分。未磷酸化的III（Glc）通过与不同的靶蛋白结合来抑制非PTS碳水化合物转运系统。在2.6埃分辨率的晶体结构的目标之一，甘油激酶（GK），在与未磷酸化的III（葡萄糖），甘油，和腺苷二磷酸复合物进行了测定。GK含有一个区域，其拓扑结构与己糖激酶的三磷酸腺苷结合域、70 kD热休克同源物和肌动蛋白相同。III（Glc）结合远离GK的催化位点，表明长程构象变化介导III（Glc）对GK的抑制。GK和III（Glc）通过疏水和静电相互作用结合，只有一个氢键涉及不带电基团。III（Glc）的磷酸化位点His 90被掩埋在由III（Glc）的活性位点区域和GK的3（10）螺旋形成的疏水环境中，表明磷酸化通过直接破坏蛋白质-蛋白质相互作用来阻止III（Glc）与GK结合。
The phosphocarrier protein III(Glc) is an integral component of the bacterial phosphotransferase (PTS) system. Unphosphorylated III(Glc) inhibits non-PTS carbohydrate transport systems by binding to diverse target proteins. The crystal structure at 2.6 angstrom resolution of one of the targets, glycerol kinase (GK), in complex with unphosphorylated III(Glc), glycerol, and adenosine diphosphate was determined. GK contains a region that is topologically identical to the adenosine triphosphate binding domains of hexokinase, the 70-kD heat shock cognate, and actin. III(Glc) binds far from the catalytic site of GK, indicating that long-range conformational changes mediate the inhibition of GK by III(Glc). GK and III(Glc) are bound by hydrophobic and electrostatic interactions, with only one hydrogen bond involving an uncharged group. The phosphorylation site of III(Glc), His90, is buried in a hydrophobic environment formed by the active site region of III(Glc) and a 3(10) helix of GK, suggesting that phosphorylation prevents III(Glc) binding to GK by directly disrupting protein-protein interactions.