Walker S, Hayes S, O'Hare P
Marie Curie Research Institute, Oxted, Surrey, England.
Cell. 1994 Dec 2;79(5):841-52. doi: 10.1016/0092-8674(94)90073-6.
We show that the presence of a regulatory cis-acting element that flanks the core octamer site and dictates selectivity in the response to Vmw65 (VP16), while dispensable for POU binding per se, induces a conformational alteration in the nature of the POU domain in the DNA complex. A single substitution in the flanking signal distorts the POU complex and without affecting overall POU binding prevents Vmw65 interaction. Alternatively, substitution of a residue in the homeodomain predicted to contact the GARAT region prevents its recognition even on a wild-type motif, causing a reversion to the DNA binding pattern seen on a cellular motif and at the same time inefficient recognition by Vmw65. The results indicate that Vmw65 recognizes a particular POU domain conformation induced by the presence of the flanking GARAT region.
我们发现，核心八聚体位点侧翼存在一个调控性顺式作用元件，它决定了对Vmw65（VP16）反应的选择性，虽然其本身对于POU结合并非必需，但会在DNA复合物中诱导POU结构域性质的构象改变。侧翼信号中的单个取代会扭曲POU复合物，并且在不影响整体POU结合的情况下阻止Vmw65相互作用。另外，预测与GARAT区域接触的同源结构域中的一个残基被取代，即使在野生型基序上也会阻止其识别，导致恢复到在细胞基序上看到的DNA结合模式，同时Vmw65的识别效率低下。结果表明，Vmw65识别由侧翼GARAT区域的存在诱导的特定POU结构域构象。
