Lin S L, Tsai C J, Nussinov R
Laboratory of Mathematical Biology, NCI-FCRF, MD 21702, USA.
J Mol Biol. 1995 Apr 21;248(1):151-61. doi: 10.1006/jmbi.1995.0208.
Four-helix bundles are identified and characterized in the subunit interfaces of protein multimers. We find that this motif occurs as often in the interfaces as in the protein monomers. Common and different characteristics demonstrated by the bundles in the two environments suggest the possible stabilization mechanisms of the bundles via cooperative helical twist, dipole alignment and interhelical connections. Nucleation of parallel helix pairs may be a favourable pathway before the pairs couple into bundles during folding. Certain properties found chaotic in the interface four-helix bundles indicate that either the subunit association is far from the global minimum conformation, or that the footprints of the folding pathway are recorded in these properties.
在蛋白质多聚体的亚基界面中识别并表征了四螺旋束。我们发现，这种基序在界面中出现的频率与在蛋白质单体中一样高。在这两种环境中，束所表现出的共同和不同特征表明，通过协同螺旋扭曲、偶极排列和螺旋间连接，束可能存在稳定机制。在折叠过程中，平行螺旋对在耦合形成束之前，其成核可能是一条有利的途径。在界面四螺旋束中发现的某些混沌性质表明，要么亚基缔合远非全局最小构象，要么折叠途径的痕迹记录在这些性质中。
