HOMOLOGY MODELLING & STRUCTURAL STUDIES OF MERCURIC ION REDUCTASE

汞还原酶是巯基还原酶家族的一员 氧化还原酶，其中包括谷胱甘肽还原酶 和硫辛酰胺脱氢酶。 在我们的研究中， 汞还原酶是一种同源二聚体， 替代站点机制，一方面涉及理解 在催化循环过程中发生的结构变化。 近日一 芽孢杆菌属物种RC 607汞还原酶的晶体结构是 至少有两种形式（有和没有NADP）。 但大多数 已经进行的生物化学研究集中在P. 铜绿假单胞菌Tn501汞还原酶。 Tn501酶还没有被发现。 结晶 RC 607和Tn 501汞还原酶具有40%的相同性 in their其sequences序列. 预计它们的结构高度 同源的 该程序看，可通过计算机图形 实验室，使用两个序列的比对来产生一个 二聚体的同源性模型。 借助CGL的工作站， 程序，我们能够可视化可能的相互作用， 在不对称性中发挥作用， 周期 通过比较Tn501酶的生成模型， 与已知的RC607酶的结构相比，我们将能够 将可能相关的相似性和差异性可视化 与我们从这些生物中获得的生化信息相结合， 内切酶 我们想建立一个催化循环的结构模型 并了解站点间通信的结构路径。 从同源性模型获得的信息将使我们能够 构建其活性位点通讯被破坏的突变酶。

Mercuric reductase is a member of the family of thiol oxidoreductases which, among others, includes glutathione reductase and lipoamide dehydrogenase. In our investigation of the catalytic mechanism of Mercuric Reductase, a homodimer that undergoes an alternate-site mechanism, one aspect involves understanding the structural changes that occur during the catalytic cycle. Recently, a crystal structure of the Bacillus sp. RC607 mercuric reductase was solved in at least two forms (with and without NADP). However, most of the biochemical studies that have been conducted focus on P. aeruginosa Tn501 mercuric reductase. The Tn501 enzyme has yet to be crystallized. RC607 and Tn501 mercuric reductases are 40% identical in their sequences. It is expected that their structures be highly homologous. The program LOOK, available through the Computer Graphics Laboratory, uses the alignment of the two sequences to ge nerate a homology model of the dimer. With the aid of CGL's workstations and programs, we were able to visualize possible interactions that may play a role in the asymmetry that develops through the catalytic cycle. From a comparison of the generated models of Tn501 enzyme against the known structure of the RC607 enzyme, we will be able to visualize similarities as well as differences that may be correlated with the biochemical information that we are also obtaining from these enzymes. We want to develop a structural model of the catalytic cycle and understand the structural pathway(s) of intersite communication. Information obtained from the homology models will allow us to construct mutant enzymes whose active site communication is disrupted.