DYNAMICS OF BACTERIOPHAGE-T4 DNA-POLYMERASE FUNCTION - IDENTIFICATION OF AMINO-ACID-RESIDUES THAT AFFECT SWITCHING BETWEEN POLYMERASE AND 3'-]5'-EXONUCLEASE ACTIVITIES

被引：80

作者：

STOCKI, SA ^{[1
]}

NONAY, RL ^{[1
]}

REHAKRANTZ, LJ ^{[1
]}

机构：

[1] UNIV ALBERTA,DEPT SCI BIOL,EDMONTON,AB T6G 2E9,CANADA

来源：

JOURNAL OF MOLECULAR BIOLOGY | 1995年 / 254卷 / 01期

基金：

加拿大自然科学与工程研究理事会;

关键词：

DYNAMICS OF DNA POLYMERASE FUNCTION; GENETIC ANALYSIS; PARTITIONING BETWEEN POLYMERASE AND 3'-]5' EXONUCLEASE ACTIVITIES; NUCLEOTIDE TURNOVER; DNA REPLICATION FIDELITY;

D O I：

10.1006/jmbi.1995.0595

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：

Many DNA polymerases are multifunctional with the ability to replicate DNA as well as to proofread misincorporated nucleotides. Since polymerase and 3' --> 5' exonuclease activities appear to reside in spatially distinct active centers, there must be some mechanism for coordinating replication with proofreading and for transferring DNA between the two active centers. We have designed a genetic selection scheme to isolate bacteriophage T4 mutant DNA polymerases that are defective in ''switching'' between polymerase and exonuclease activities. Amino acid residues that affected active-site-switching were identified in four regions of the T4 DNA polymerase: two regions in the proposed polymerase domain and two regions in the proposed exonuclease domain. Representative mutant DNA polymerases from each region were purified for biochemical studies. We propose that amino acid substitutions identified by mutational analysis affect critical contacts between T4 DNA polymerase and DNA that are required for transfer of DNA between the polymerase and exonuclease active centers. (C) 1995 Academic Press Limited

引用

页码：15 / 28

页数：14

共 54 条

[51] FUNCTIONS OF REPLICATION FACTOR-C AND PROLIFERATING-CELL NUCLEAR ANTIGEN - FUNCTIONAL SIMILARITY OF DNA-POLYMERASE ACCESSORY PROTEINS FROM HUMAN-CELLS AND BACTERIOPHAGE-T4 [J].