Niefind K, Guerra B, Pinna L A, Issinger O G, Schomburg D
Universität zu Köln, Institut für Biochemie, Zülpicher Strasse 47, D-50674 Köln, Germany.
EMBO J. 1998 May 1;17(9):2451-62. doi: 10.1093/emboj/17.9.2451.
CK2alpha is the catalytic subunit of protein kinase CK2, an acidophilic and constitutively active eukaryotic Ser/Thr kinase involved in cell proliferation. A crystal structure, at 2.1 A resolution, of recombinant maize CK2alpha (rmCK2alpha) in the presence of ATP and Mg2+, shows the enzyme in an active conformation stabilized by interactions of the N-terminal region with the activation segment and with a cluster of basic residues known as the substrate recognition site. The close interaction between the N-terminal region and the activation segment is unique among known protein kinase structures and probably contributes to the constitutively active nature of CK2. The active centre is occupied by a partially disordered ATP molecule with the adenine base attached to a novel binding site of low specificity. This finding explains the observation that CK2, unlike other protein kinases, can use both ATP and GTP as phosphorylating agents.
CK2α是蛋白激酶CK2的催化亚基，CK2是一种嗜酸性且组成型活性的真核丝氨酸/苏氨酸激酶，参与细胞增殖。在ATP和Mg2+存在的情况下，重组玉米CK2α（rmCK2α）的分辨率为2.1埃的晶体结构显示，该酶处于活性构象，通过N端区域与激活片段以及与称为底物识别位点的碱性残基簇的相互作用而稳定。N端区域与激活片段之间的紧密相互作用在已知的蛋白激酶结构中是独特的，可能有助于CK2的组成型活性性质。活性中心被一个部分无序的ATP分子占据，腺嘌呤碱基连接到一个低特异性的新结合位点。这一发现解释了与其他蛋白激酶不同，CK2可以使用ATP和GTP作为磷酸化剂的现象。
