Regulation of B family DNA polymerase fidelity by a conserved active site residue: characterization of M644W, M644L and M644F mutants of yeast DNA polymerase epsilon.
Regulation of B family DNA polymerase fidelity by a conserved active site residue: characterization of M644W, M644L and M644F mutants of yeast DNA polymerase epsilon.
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DOI：
10.1093/nar/gkm132
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发表时间：
2007
影响因子：
14.9
通讯作者：
Kunkel TA
中科院分区：
文献类型：
--
作者：
Pursell ZF;Isoz I;Lundström EB;Johansson E;Kunkel TA
为了更好地了解 DNA 聚合酶 ε (Pol ε) 的功能和保真度，我们在此报告了用亮氨酸、色氨酸或苯丙氨酸取代 Met644 的酵母 Pol ε 突变体的保真度。 Met644 侧链与不变的酪氨酸相互作用，该酪氨酸接触传入的 dNTP 的糖。 M644W 和 M644L Pol ε 以高保真度合成 DNA，但 M644F Pol ε 由于错插率大幅增加而降低了保真度。当依赖于Msh6的复制错误修复有缺陷时，pol2-M644F菌株的突变率比野生型Polε菌株的突变率高16倍。结合早期对酵母 Pol α (L868M/F) 和 Pol δ (L612M) 中同源氨基酸替换的低保真突变体的研究，这些数据表明 Pol ε 中 Met644 占据的活性位点位置是所有三个 B 家族复制聚合酶复制保真度的关键决定因素。有趣的是，M644F Pol ε 的错误特异性与 L868M/F Pol α 或 L612M Pol δ 的错误特异性不同，这意味着每种聚合酶具有不同的活性位点几何形状，并表明这些聚合酶等位基因可能会产生独特的突变特征以探测体内功能。
To better understand the functions and fidelity of DNA polymerase ε (Pol ε), we report here on the fidelity of yeast Pol ε mutants with leucine, tryptophan or phenylalanine replacing Met644. The Met644 side chain interacts with an invariant tyrosine that contacts the sugar of the incoming dNTP. M644W and M644L Pol ε synthesize DNA with high fidelity, but M644F Pol ε has reduced fidelity resulting from strongly increased misinsertion rates. When Msh6-dependent repair of replication errors is defective, the mutation rate of a pol2-M644F strain is 16-fold higher than that of a strain with wild-type Pol ε. In conjunction with earlier studies of low-fidelity mutants with replacements for the homologous amino acid in yeast Pol α (L868M/F) and Pol δ (L612M), these data indicate that the active site location occupied by Met644 in Pol ε is a key determinant of replication fidelity by all three B family replicative polymerases. Interestingly, error specificity of M644F Pol ε is distinct from that of L868M/F Pol α or L612M Pol δ, implying that each polymerase has different active site geometry, and suggesting that these polymerase alleles may generate distinctive mutational signatures for probing functions in vivo.
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影响因子：
64.5
作者：
Franklin, MC;Wang, JM;Steitz, TA
通讯作者：
Steitz, TA
DOI：
10.1073/pnas.032457899
发表时间：
2002-02-05
影响因子：
11.1
作者：
Minnick, DT;Liu, LX;Joyce, CM
通讯作者：
Joyce, CM
DOI：
10.1073/pnas.88.21.9473
发表时间：
1991-11-01
影响因子：
11.1
作者：
MORRISON, A;BELL, JB;SUGINO, A
通讯作者：
SUGINO, A
影响因子：
4.8
作者：
da Silva, EF;Mandal, SS;Reha-Krantz, LJ
通讯作者：
Reha-Krantz, LJ
影响因子：
5.3
作者：
Niimi, A;Limsirichaikul, S;Suzuki, M
通讯作者：
Suzuki, M