Effect of deoxyribopolymers and ribopolymers on the sensitivity of the cyclic-AMP receptor protein of Escherichia coli to proteolytic attack.
Effect of deoxyribopolymers and ribopolymers on the sensitivity of the cyclic-AMP receptor protein of Escherichia coli to proteolytic attack.
复制标题
脱氧核糖聚合物和核糖聚合物对大肠杆菌环AMP受体蛋白对蛋白水解攻击敏感性的影响。
DOI：
10.1016/0003-9861(85)90600-9
复制
发表时间：
1985
影响因子：
3.9
通讯作者：
Krakow,JS
中科院分区：
文献类型：
--
作者：
Angulo,JA;Krakow,JS
cAMP受体蛋白（CRP）是一种变构蛋白，其中cAMP的结合引起构象变化，从而增加对DNA的亲和力。未配体的CRP对各种蛋白酶（胰蛋白酶、枯草杆菌蛋白酶、金黄色葡萄球菌V8蛋白酶、梭菌蛋白酶、胰凝乳蛋白酶）的攻击相对具有抗性，这些蛋白酶切割cAMP-CRP，产生失去DNA结合活性的N-末端核心。cAMP-CRP与双链脱氧核糖核苷酸和小牛胸腺DNA的结合可保护小牛胸腺免受胰蛋白酶、枯草杆菌蛋白酶、S. aureusV 8蛋白酶和梭菌蛋白酶。这种cAMP-CRP-DNA复合物对胰凝乳蛋白酶的攻击保持敏感。在所测试的单链脱氧和核糖多核苷酸中，只有r（I）n和r（A）n对这些蛋白酶的攻击具有显著的保护作用（胰凝乳蛋白酶除外）。由于胰蛋白酶（Lys 130）和枯草杆菌蛋白酶（Leu 116）的切割位点不是C-末端DNA结合结构域的一部分，因此似乎DNA的结合可能使cAMP-CRP的其他区域发生构象变化。
The cAMP receptor protein (CRP) is an allosteric protein in which binding of cAMP effects a conformational change with a consequent increased affinity for DNA. Unliganded CRP is relatively resistant to attack by a variety of proteases (trypsin, subtilisin,Staphylococcus aureusV8 protease, clostripain, chymotrypsin) which cleave cAMP-CRP, producing N-terminal cores which have lost DNA binding activity. Binding of double-stranded deoxyribopolynucleotides and calf thymus DNA by cAMP-CRP confers protection against attack by trypsin, subtilisin,S. aureusV8 protease, and clostripain. Such cAMP-CRP-DNA complexes remain sensitive to attack by chymotrypsin. Of the single-stranded deoxy- and ribopolynucleotides tested, only r(I)n and r(A)n gave significant protection against attack by these proteases (with the exception of chymotrypsin). Since the cutting sites for trypsin (Lys 130) and subtilisin (Leu 116) are not part of the C-terminal DNA binding domain, it would appear that binding of DNA may confer conformational changes on other regions of cAMP-CRP.