DNA binding provides a molecular strap activating the adenovirus proteinase
DNA binding provides a molecular strap activating the adenovirus proteinase
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DOI：
10.1074/mcp.m400037-mcp200
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发表时间：
2004-10-01
影响因子：
7
通讯作者：
Chance, MR
中科院分区：
文献类型：
--
作者：
Gupta, S;Mangel, WF;Chance, MR
人腺病毒蛋白酶（AVP）需要两个辅助因子才能发挥最大的活性：pVIc，一种从腺病毒前体蛋白pVI的C端衍生的肽，以及病毒DNA。同步加速器蛋白足迹用于绘制溶剂可接近的辅因子结合位点，并确定与辅因子结合相关的构象变化。当pVIc单独或与DNA结合到AVP上时，AVP两个亚结构域之间的活性位点间隙附近会发生显著的构象变化。此外，当DNA与AVP结合时，观察到两个主要亚结构域上的特定残基明显受到羟基自由基的保护。基于AVP中这些受保护的侧链残基以及保守的芳香残基和带正电的残基的位置，构建了DNA结合的三维模型。该模型表明，DNA结合可以改变两个AVP结构域的相对取向，导致AVP被DNA部分激活。此外，pVIc和DNA既可以单独改变活性位点构象，也可以共同驱动活性位点构象，从而充分激活AVP。
Human adenovirus proteinase (AVP) requires two cofactors for maximal activity: pVIc, a peptide derived from the C terminus of adenovirus precursor protein pVI, and the viral DNA. Synchrotron protein footprinting was used to map the solvent accessible cofactor binding sites and to identify conformational changes associated with the binding of cofactors to AVP. The binding of pVIc alone or pVIc and DNA together to AVP triggered significant conformational changes adjacent to the active site cleft sandwiched between the two AVP subdomains. In addition, upon binding of DNA to AVP, it was observed that specific residues on each of the two major subdomains were significantly protected from hydroxyl radicals. Based on the locations of these protected side-chain residues and conserved aromatic and positively charged residues within AVP, a three-dimensional model of DNA binding was constructed. The model indicated that DNA binding can alter the relative orientation of the two AVP domains leading to the partial activation of AVP by DNA. In addition, both pVIc and DNA may independently alter the active site conformation as well as drive it cooperatively to fully activate AVP.