Assa-Munt N, Mortishire-Smith R J, Aurora R, Herr W, Wright P E
Department of Molecular Biology, Scripps Research Institute, La Jolla, California 92037.
Cell. 1993 Apr 9;73(1):193-205. doi: 10.1016/0092-8674(93)90171-l.
The POU-specific (POUs) domain, in association with a POU-type homeodomain, forms the bipartite DNA-binding POU domain. The solution structure of the Oct-1 POUs domain has been determined by multidimensional nuclear magnetic resonance spectroscopy and consists of four alpha helices surrounding a conserved hydrophobic core. The POUs domain is structurally similar to the DNA-binding domains of the bacteriophage lambda and 434 repressors and 434 Cro. These domains exhibit superimposable helix-turn-helix (HTH) motifs, except that in the POUs domain, the first helix and the linker to the second helix of the motif are extended. The conserved structural features have been used to propose a plausible model for DNA binding by the POUs domain. A human dwarfism mutation that affects positive control in the related POU domain protein Pit-1 maps to the same region of the HTH motif as do positive control mutations in lambda repressor.
POU特异性（POUs）结构域与POU型同源结构域结合，形成二分体DNA结合POU结构域。Oct-1 POUs结构域的溶液结构已通过多维核磁共振光谱确定，由围绕保守疏水核心的四个α螺旋组成。POUs结构域在结构上类似于噬菌体λ和434阻遏物以及434 Cro的DNA结合结构域。这些结构域表现出可叠加的螺旋-转角-螺旋（HTH）基序，只是在POUs结构域中，基序的第一个螺旋和与第二个螺旋的连接区有所延长。保守的结构特征已被用于提出一个关于POUs结构域与DNA结合的合理模型。一个影响相关POU结构域蛋白Pit-1中正向调控的人类侏儒症突变，与λ阻遏物中的正向调控突变定位在HTH基序的同一区域。
