CRYSTAL-STRUCTURE OF A CAP-DNA COMPLEX - THE DNA IS BENT BY 90-DEGREES
CRYSTAL-STRUCTURE OF A CAP-DNA COMPLEX - THE DNA IS BENT BY 90-DEGREES
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DOI：
10.1126/science.1653449
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发表时间：
1991-08-30
期刊：
影响因子：
56.9
通讯作者：
STEITZ, TA
中科院分区：
文献类型：
--
作者：
SCHULTZ, SC;SHIELDS, GC;STEITZ, TA
大肠杆菌分解代谢基因激活蛋白(CAP)与30个碱基对的DNA序列的3埃分辨晶体结构表明，DNA发生了90度的弯曲。这种弯曲几乎完全是由发生在TG/CA碱基对之间的两个40度扭曲造成的，这两个碱基对位于复合体二分体轴两侧的位置5和6。CAP对DNA序列的识别既源于DNA螺旋的序列依赖扭曲，也源于DNA主沟中三个蛋白质侧链和三个碱基对暴露边之间的直接氢键作用。这种转录因子-DNA复合体的结构为转录激活的可能机制提供了洞察力。
The 3 angstrom resolution crystal structure of the Escherichia coli catabolite gene activator protein (CAP) complexed with a 30-base pair DNA sequence shows that the DNA is bent by 90-degrees. This bend results almost entirely from two 40-degrees kinks that occur between TG/CA base pairs at positions 5 and 6 on each side of the dyad axis of the complex. DNA sequence discrimination by CAP derives both from sequence-dependent distortion of the DNA helix and from direct hydrogen-bonding interactions between three protein side chains and the exposed edges of three base pairs in the major groove of the DNA. The structure of this transcription factor-DNA complex provides insights into possible mechanisms of transcription activation.