Crystal structure of the alpha, beta, gamma-tridentate manganese complex of adenosine 5'-triphosphate cocrystallized with 2,2'-dipyridylamine.
Crystal structure of the alpha, beta, gamma-tridentate manganese complex of adenosine 5'-triphosphate cocrystallized with 2,2'-dipyridylamine.
复制标题
5-三磷酸腺苷与 2,2-联吡啶胺共结晶的 α、β、γ-三齿锰复合物的晶体结构。
DOI：
10.1021/bi00347a048
复制
发表时间：
1985
期刊：
影响因子：
2.9
通讯作者：
M. Sundaralingam
中科院分区：
文献类型：
--
作者：
M. Sabat;R. Cini;T. Haromy;M. Sundaralingam
配合物的晶胞参数为：a=10.234(3)A，b=22.699(3)A，c=31.351(4)A，晶胞尺寸为a=10.234(3)A，b=22.699(3)A，c=31.351(4)A。该结构由两个共用一个锰原子的ATP分子组成。该金属与两个二元体相关的ATP分子的三磷酸链显示出α、β、伽马配位，导致六配位的Mn2+离子被六个磷酸基团包围。对于α-、β-和伽马-磷酸基团，金属到氧的距离分别为2.205(6)、2.156(4)和2.144(5)A。没有观察到金属-基团的相互作用。还有第二个六水配位的Mn2+离子也位于二分体轴上。水合锰离子夹在晶体中与磷酸盐配位的锰离子之间，金属-金属距离为5.322 A。三磷酸腺苷分子在腺嘌呤碱基的N(1)位被质子化，呈现反构象(X_1=66.0度)。呋喃核糖环为2/3T构象，假旋转参数P=179(1)度，tau m=34.1(6)度。腺嘌呤碱基在晶体二分体轴线上形成氢键自对，并与两个DPA分子堆积在一起，沿着二分体形成一列。金属-ATP复合体的结构提供了有关酶中核苷三磷酸底物可能的金属配位、构象和环境的信息。
The 1:1:1 complex of Mn2+, ATP, and 2,2'-dipyridylamine (DPA) crystallizes as Mn-(HATP)2.Mn(H2O)6.(HDPA)2.12H2O in the orthorhombic space group C222(1) with unit cell dimensions a = 10.234 (3) A, b = 22.699 (3) A, and c = 31.351 (4) A. The structure was solved by the multisolution technique and refined by the least-squares method to a final R index of 0.072 using 3516 intensities. The structure is composed of two ATP molecules sharing a common manganese atom. The metal exhibits alpha, beta, gamma coordination to the triphosphate chains of two dyad-related ATP molecules, resulting in a hexacoordinated Mn2+ ion surrounded by six phosphate groups. The metal to oxygen distances are 2.205 (6), 2.156 (4), and 2.144 (5) A for the alpha-, beta-, and gamma-phosphate groups, respectively. No metal-base interactions are observed. There is a second hexaaqua-coordinated Mn2+ ion that is also located on a dyad axis. The hydrated manganese ions sandwich the phosphate-coordinated manganese ions in the crystal with a metal-metal distance of 5.322 A. The ATP molecule is protonated on the N(1) site of the adenine base and exhibits the anti conformation (chi = 66.0 degrees). The ribofuranose ring is in the 2/3 T conformation with pseudorotation parameters P = 179 (1) degrees and tau m = 34.1 (6) degrees. The adenine bases form hydrogen-bonded self-pairs across a crystallographic dyad axis and stack with both DPA molecules to form a column along the dyad. The structure of the metal-ATP complex provides information about the possible metal coordination, conformation, and environment of the nucleoside triphosphate substrate in the enzyme.