SITE-DIRECTED MUTAGENESIS CLARIFIES THE SUBSTRATE POSITION WITHIN THE 3-DIMENSIONAL MODEL OF THE ACTIVE-SITE OF HERPES-SIMPLEX VIRUS TYPE-1 THYMIDINE KINASE

被引:6
作者
MICHAEL, M [1 ]
FETZER, J [1 ]
FOLKERS, G [1 ]
机构
[1] ETH ZURICH,DEPT PHARM,CH-8057 ZURICH,SWITZERLAND
来源
EUROPEAN JOURNAL OF BIOCHEMISTRY | 1994年 / 226卷 / 01期
关键词
D O I
10.1111/j.1432-1033.1994.tb20044.x
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Site-directed mutagenesis was used to experimentally verify the 3D model of the active site of herpes simplex virus type-1 thymidine kinase (HSV 1 TK) obtained by homology modelling. For this purpose, D215 and K317 were replaced by R and G, respectively, at homologous positions in the aciclovir-insensitive bovine herpes virus type-1 thymidine kinase (BHV 1 TK). Wild-type and mutated enzymes were expressed in Escherichia coli using a gene fusion vector and purified to homogeneity. While both mutants had the same K-m value for thymidine as the recombinant wildtype enzyme (0.2 mu M), V-max was decreased to 20-25% of the original wild-type value. The recombinant wild-type enzyme was inhibited by the substrate analogue aciclovir with a K-i of 146 mu M. Both mutants were able to phosphorylate aciclovir to about the same extent as the wild-type enzyme. These findings suggest that neither D215 nor K317 are directly involved in substrate binding. Therefore, a rearrangement of the 3D model is suggested, concerning the assignment of the substrate-binding site and co-substrate-binding site at the right and left side of the phosphate-binding loop, respectively.
引用
收藏
页码:219 / 226
页数:8
相关论文
共 25 条
[1]   HERPESVIRAL DEOXYTHYMIDINE KINASES CONTAIN A SITE ANALOGOUS TO THE PHOSPHORYL-BINDING ARGININE-RICH REGION OF PORCINE ADENYLATE KINASE - COMPARISON OF SECONDARY STRUCTURE PREDICTIONS AND CONSERVATION [J].
BALASUBRAMANIAM, NK ;
VEERISETTY, V ;
GENTRY, GA .
JOURNAL OF GENERAL VIROLOGY, 1990, 71 :2979-2987
[2]   IDENTIFICATION OF IMPORTANT RESIDUES WITHIN THE PUTATIVE NUCLEOSIDE BINDING-SITE OF HSV-1 THYMIDINE KINASE BY RANDOM SEQUENCE SELECTION - ANALYSIS OF SELECTED MUTANTS IN-VITRO [J].
BLACK, ME ;
LOEB, LA .
BIOCHEMISTRY, 1993, 32 (43) :11618-11626
[3]  
BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248, DOI 10.1016/0003-2697(76)90527-3
[4]  
CHEN MS, 1979, J BIOL CHEM, V254, P747
[5]  
CHEN MS, 1978, J BIOL CHEM, V253, P1325
[6]  
CHENG YC, 1976, J BIOL CHEM, V251, P2605
[7]  
COEN DM, 1992, SEMIN VIROL, V3, P3
[8]   3-DIMENSIONAL STRUCTURE OF THE COMPLEX BETWEEN THE MITOCHONDRIAL MATRIX ADENYLATE KINASE AND ITS SUBSTRATE AMP [J].
DIEDERICHS, K ;
SCHULZ, GE .
BIOCHEMISTRY, 1990, 29 (35) :8138-8144
[9]   SELECTIVITY OF ACTION OF AN ANTI-HERPETIC AGENT, 9-(2-HYDROXYETHOXYMETHYL)GUANINE [J].
ELION, GB ;
FURMAN, PA ;
FYFE, JA ;
DEMIRANDA, P ;
BEAUCHAMP, L ;
SCHAEFFER, HJ .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1977, 74 (12) :5716-5720
[10]  
FETZER J, 1994, IN PRESS PROT EXPR P, V5