Hurley J H
Laboratory of Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0580, USA.
Annu Rev Biophys Biomol Struct. 1996;25:137-62. doi: 10.1146/annurev.bb.25.060196.001033.
Sugar kinases, stress-70 proteins, and actin belong to a superfamily defined by a fold consisting of two domains with the topology beta beta beta alpha beta alpha beta alpha. These enzymes catalyze ATP phosphoryl transfer or hydrolysis coupled to a large conformational change in which the two domains close around the nucleotide. The beta 1-beta 2 turns of each domain form hydrogen bonds with ATP phosphates, and conserved Asp, Glu or Gln residues coordinate Mg2+ or Ca2+ through bound waters. The activity of superfamily members is regulated by various effectors, some of which act by promoting or inhibiting the conformational change. Nucleotide hydrolysis eliminates interdomain bridging interactions between the second beta 1-beta 2 turn and the ATP gamma-phosphate. This is proposed to destabilize the closed conformation and affect the orientation of the two domains, which might in turn regulate the activity of kinase oligomers, stress-70 protein-protein complexes, and actin filaments.
糖激酶、应激-70蛋白和肌动蛋白属于一个超家族，该超家族由一种折叠结构定义，这种折叠结构由两个结构域组成，其拓扑结构为βββαβαβα。这些酶催化ATP磷酸基转移或水解，并伴随着一个大的构象变化，在这个变化过程中，两个结构域围绕核苷酸闭合。每个结构域的β1-β2转角与ATP磷酸基团形成氢键，保守的天冬氨酸、谷氨酸或谷氨酰胺残基通过结合水与Mg2+或Ca2+配位。超家族成员的活性受多种效应物调节，其中一些效应物通过促进或抑制构象变化来发挥作用。核苷酸水解消除了第二个β1-β2转角与ATPγ-磷酸基团之间的结构域间桥连相互作用。这被认为会使闭合构象不稳定，并影响两个结构域的取向，进而可能调节激酶寡聚体、应激-70蛋白-蛋白复合物和肌动蛋白丝的活性。
