Buried polar residues in coiled-coil interfaces
Buried polar residues in coiled-coil interfaces
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DOI：
10.1021/bi002829w
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发表时间：
2001-05-29
期刊：
影响因子：
2.9
通讯作者：
Kim, PS
中科院分区：
文献类型：
--
作者：
Akey, DL;Malashkevich, VN;Kim, PS
卷曲螺旋，估计在大多数基因组中占编码残基的3-5%，其特征在于七肽重复，（abcdefg）（n），其中埋藏的a和d位置形成多个cl-螺旋之间的界面。虽然通常是疏水性的，但这些a-和d-位残基的相当大一部分（类似于20%）是极性或带电的。我们构建了具有良好特征的卷曲螺旋GCN 4-p1的变体，其在a或d位置具有单个极性残基（Asn、Gln、Ser或Thr）。测量每个变体的稳定性和寡聚特异性，并确定在a或d位置具有苏氨酸或丝氨酸的卷曲螺旋三聚体的晶体结构。的结构显示如何在界面上的单一极性残基不仅影响局部包装，但也整体卷曲螺旋几何形状的变化所看到的克里克超螺旋参数和芯腔体积。
Coiled coils, estimated to constitute 3-5% of the encoded residues in most genomes, are characterized by a heptad repeat, (abcdefg)(n), where the buried a and d positions form the interface between multiple cl-helices. Although generally hydrophobic, a substantial fraction (similar to 20%) of these a- and d-position residues are polar or charged. We constructed variants of the well-characterized coiled coil GCN4-p1 with a single polar residue (Asn, Gin, Ser, or Thr) at either an a or a d position. The stability and oligomeric specificity of each variant were measured, and crystal structures of coiled-coil trimers with threonine or serine at either an a or a d position were determined. The structures show how single polar residues in the interface affect not only local packing, but also overall coiled-coil geometry as seen by changes in the Crick supercoil parameters and core cavity volumes.