CRYSTAL-STRUCTURE OF AN ENGRAILED HOMEODOMAIN-DNA COMPLEX AT 2.8-A RESOLUTION - A FRAMEWORK FOR UNDERSTANDING HOMEODOMAIN-DNA INTERACTIONS
CRYSTAL-STRUCTURE OF AN ENGRAILED HOMEODOMAIN-DNA COMPLEX AT 2.8-A RESOLUTION - A FRAMEWORK FOR UNDERSTANDING HOMEODOMAIN-DNA INTERACTIONS
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DOI：
10.1016/0092-8674(90)90453-l
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发表时间：
1990-11-02
期刊：
影响因子：
64.5
通讯作者：
PABO, CO
中科院分区：
文献类型：
--
作者：
KISSINGER, CR;LIU, BS;PABO, CO
在2.8埃处测定了含有有锯齿的同源结构域和双链DNA位点的复合物的晶体结构。分离度，并细化到24.4%的晶体学R因子。在该复合物中，61个氨基酸多肽的两个独立区域接触TAAT亚位点。m-末端臂适合小沟，并且Arg-3和Arg-5的侧链在该“核心共有”结合位点的5“末端附近形成接触。α。Ile-47和Asn-51的侧链在TAAT位点的3“末端附近接触碱基对。这种“识别螺旋”是结构上保守的螺旋-转角-螺旋单元的一部分，但这些螺旋比在DNA中的相应螺旋长。阻遏物，螺旋-转角-螺旋单位和DNA之间的关系是显着不同的。
The crystal structure of a complex containing the engrailed homeodomain and a duplex DNA site has been determined at 2.8 .ANG. resolution and refined to a crystallographic R factor of 24.4%. In this complex, two separate regions of the 61 amino acid polypeptide contact a TAAT subsite. An m-terminal arm fits into the minor groove, and the side chains of Arg-3 and Arg-5 make contacts near the 5'' end of this "core consensus" binding site. An .alpha. helix fits into the major groove, and the side chains of Ile-47 and Asn-51 contact base pairs near the 3'' end of the TAAT site. This "recognition helix" is part of a structurally conserved helix-turn-helix unit, but these helices are longer than the corresponding helices in the .lambda. repressor, and the relationship between the helix-turn-helix unit and the DNA is significantly different.