Sequence comparison of single-stranded DNA binding proteins and its structural implications.
Sequence comparison of single-stranded DNA binding proteins and its structural implications.
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单链 DNA 结合蛋白的序列比较及其结构意义。
DOI：
10.1016/0022-2836(87)90268-3
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发表时间：
1987
影响因子：
5.6
通讯作者：
Chiu,W
中科院分区：
文献类型：
--
作者：
Prasad,BV;Chiu,W
比较了M13噬菌体基因产物5蛋白（GP 5）、Ike噬菌体PIKE、T4噬菌体基因产物32蛋白（GP 32）、大肠杆菌RecA、SSB和SSF蛋白的一级序列。这些蛋白质与单链DNA强有力地结合并协同作用，没有序列特异性。GP 5是这一组中最小的，其三维结构得到了很好的表征。使用GP 5的整个序列作为模板，我们在其他单链DNA结合蛋白中搜索芳香族和碱性残基的最佳比对区域。确定的结构域显示在这些蛋白质中的五个芳香族和四个带电残基的对齐。PIKE、GP 32和RecA中的结构域与GP 5具有统计学显著的序列同源性。这些观察结果强烈支持这类蛋白质中的蛋白质-单链DNA复合物通过芳香族残基与DNA碱基的堆积相互作用以及碱性残基与DNA磷酸基团的静电相互作用而稳定的假设。我们还发现这些蛋白质的DNA结合结构域具有相似的二级结构偏好，主要是β结构。三链β折叠可能是这些蛋白质的DNA结合结构域中的共同基序。
The primary sequences were compared among several proteins: gene product 5 protein (GP5) from phage M13; PIKE from phage Ike; gene product 32 protein (GP32) from phage T4; RecA, SSB and SSF fromEscherichia coli. These proteins bind strongly and co-operatively to single-stranded DNA with no sequence specificity. GP5 is the smallest in this group and its three-dimensional structure is well-characterized. Using the entire sequence of GP5 as a template we searched for the regions in other single-stranded DNA binding proteins yielding the best alignment of aromatic and basic residues. The identified domains show alignment of five aromatic and four charged residues in these proteins. The domains in PIKE, GP32 and RecA exhibit statistically significant sequence homology with GP5. These observations strongly favor the hypothesis that the protein-single-stranded DNA complex in this class of proteins is stabilized by the stacking interaction of the aromatic residues with the bases of the DNA, and by the electrostatic interaction of the basic residues with the phosphate groups of the DNA. We also find that the DNA binding domains of these proteins have similar secondary structural preferences, mainly β structures. The triple-stranded β-sheet may be a common motif in the DNA binding domains of these proteins.