来自流感嗜血杆菌的6-羟甲基-7,8-二氢蝶呤焦磷酸激酶的结构与功能

The structure and function of the 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase from Haemophilus influenzae.

作者信息

Hennig M, Dale G E, D'arcy A, Danel F, Fischer S, Gray C P, Jolidon S, Müller F, Page M G, Pattison P, Oefner C

机构信息

F. Hoffmann-La Roche Ltd, Pharma Preclinical Research, Basel, CH-4070, Switzerland.

出版信息

J Mol Biol. 1999 Mar 26;287(2):211-9. doi: 10.1006/jmbi.1999.2623.

DOI:10.1006/jmbi.1999.2623

PMID:10080886

Abstract

The gene encoding the 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase of Haemophilus influenzae has been cloned and expressed in Escherichia coli. A complex of the purified protein with a substrate analog has been crystallized and its structure solved by multiple anomalous dispersion using phase information obtained from a single crystal of selenomethione-labeled protein. The enzyme folds into a four-stranded antiparallel beta-sheet flanked on one side by two alpha-helices and on the other by three consecutive alpha-helices, giving a novel beta1alpha1beta2beta3alpha2beta4alpha3alpha4alpha5 polypeptide topology. The three-dimensional structure of a binary complex has been refined at 2.1 A resolution. The location of the substrate analog and a sulfate ion gives important insight into the molecular mechanism of the enzyme.

摘要

流感嗜血杆菌编码6-羟甲基-7,8-二氢蝶呤焦磷酸激酶的基因已被克隆并在大肠杆菌中表达。纯化后的蛋白质与底物类似物的复合物已被结晶，并利用从硒代甲硫氨酸标记蛋白质的单晶获得的相位信息，通过多波长反常散射法解析了其结构。该酶折叠成一个四链反平行β-折叠片层，一侧由两个α-螺旋环绕，另一侧由三个连续的α-螺旋环绕，形成一种新颖的β1α1β2β3α2β4α3α4α5多肽拓扑结构。二元复合物的三维结构已在2.1埃分辨率下得到优化。底物类似物和硫酸根离子的位置为该酶的分子机制提供了重要的见解。