Graham Debbie L, Lowe Peter N, Grime Geoffrey W, Marsh Michael, Rittinger Katrin, Smerdon Stephen J, Gamblin Steven J, Eccleston John F
Computational & Structural Sciences, GlaxoSmithKline, Gunnels Wood Road, Stevenage, Herts, United Kingdom.
Chem Biol. 2002 Mar;9(3):375-81. doi: 10.1016/s1074-5521(02)00112-6.
The formation of complexes between small G proteins and certain of their effectors can be facilitated by aluminum fluorides. Solution studies suggest that magnesium may be able to replace aluminum in such complexes. We have determined the crystal structure of RhoA.GDP bound to RhoGAP in the presence of Mg(2+) and F(-) but without Al(3+). The metallofluoride adopts a trigonal planar arrangement instead of the square planar structure of AlF(4)(-). We have confirmed that these crystals contain magnesium and not aluminum by proton-induced X-ray emission spectroscopy. The structure adopted by GDP.MgF(-) possesses the stereochemistry and approximate charge expected for the transition state. We suggest that MgF3(-) may be the reagent of choice for studying phosphoryl transfer reactions.
小G蛋白与其某些效应器之间复合物的形成可由氟化铝促进。溶液研究表明，镁可能能够在这类复合物中取代铝。我们已经确定了在存在Mg(2+)和F(-)但不存在Al(3+)的情况下，与RhoGAP结合的RhoA.GDP的晶体结构。金属氟化物采用三角平面排列，而不是AlF(4)(-)的四方平面结构。我们通过质子诱导X射线发射光谱法证实这些晶体含有镁而非铝。GDP.MgF(-)所采用的结构具有过渡态预期的立体化学和近似电荷。我们认为MgF3(-)可能是研究磷酰基转移反应的首选试剂。
