Crystal structures of the Klenow fragment of Thermus aquaticus DNA polymerase I complexed with deoxyribonucleoside triphosphates
Crystal structures of the Klenow fragment of Thermus aquaticus DNA polymerase I complexed with deoxyribonucleoside triphosphates
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DOI：
10.1002/pro.5560070505
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发表时间：
1998-05-01
期刊：
影响因子：
8
通讯作者：
Waksman, G
中科院分区：
文献类型：
--
作者：
Li, Y;Kong, Y;Waksman, G
水生栖热菌DNA聚合酶I（Klentaql）的Klenow片段与四种脱氧核苷三磷酸（dNTP）复合的晶体结构已被确定为2.5埃分辨率。dNTP与Klentaql的O螺旋相邻结合。三磷酸基团在所有四种复合物中几乎位于相同的位置，并由三个带正电荷的残基Arg 659、Lys 663和Arg 587以及两个极性残基His 639和Gln 613锚定。Klentaql/dNTP复合物中碱基部分的构型显示出变异性，表明dNTP结合主要由磷酸部分的识别和结合决定。然而，当叠加在标签聚合酶/平端DNA复合物结构上时（Eom等人，1996），两个dNTP/Klentaql结构证明了核苷酸碱基与DNA引物链的3'末端的适当堆叠，表明至少在这两个二元复合物中，观察到的dNTP构象在功能上是相关的。
The crystal structures of the Klenow fragment of the Thermus aquaticus DNA polymerase I (Klentaql) complexed with four deoxyribonucleoside triphosphates (dNTP) have been determined to 2.5 Angstrom resolution. The dNTPs bind adjacent to the O helix of Klentaql. The triphosphate moieties are at nearly identical positions in all four complexes and are anchored by three positively charged residues, Arg659, Lys663, and Arg587, and by two polar residues, His639 and Gln613. The configuration of the base moieties in the Klentaql/dNTP complexes demonstrates variability suggesting that dNTP binding is primarily determined by recognition and binding of the phosphate moiety. However, when superimposed on the Tag polymerase/blunt end DNA complex structure (Eom et al., 1996), two of the dNTP/Klentaql structures demonstrate appropriate stacking of the nucleotide base with the 3' end of the DNA primer strand, suggesting that at least in these two binary complexes, the observed dNTP conformations are functionally relevant.