Ogata K, Morikawa S, Nakamura H, Sekikawa A, Inoue T, Kanai H, Sarai A, Ishii S, Nishimura Y
Graduate School of Integrated Science, Yokohama City University, Japan.
Cell. 1994 Nov 18;79(4):639-48. doi: 10.1016/0092-8674(94)90549-5.
The DNA-binding region of Myb consists of three imperfect tandem repeats (R1, R2, and R3). We have determined the solution structure of a specific DNA complex of the minimum DNA-binding domain (R2R3) by heteronuclear multidimensional NMR. Both R2 and R3 contain three helices, and the third helix in each is found to be a recognition helix. R2 and R3 are closely packed in the major groove, so that the two recognition helices contact each other directly to bind to the specific base sequence, AACNG cooperatively; this is a significant arrangement of recognition helices. The three key base pairs in this sequence are specifically recognized by Asn-183 (R3), Lys-182 (R3), and Lys-128 (R2). In contrast, R1 has no specific interactions with DNA from our NMR study of the DNA complex of the full DNA-binding domain (R1R2R3).
Myb的DNA结合区域由三个不完全的串联重复序列（R1、R2和R3）组成。我们通过异核多维核磁共振确定了最小DNA结合结构域（R2R3）的特定DNA复合物的溶液结构。R2和R3均包含三个螺旋，且发现每个中的第三个螺旋为识别螺旋。R2和R3紧密堆积在大沟中，使得两个识别螺旋直接相互接触，以协同结合特定碱基序列AACNG；这是识别螺旋的一种重要排列方式。该序列中的三个关键碱基对由Asn-183（R3）、Lys-182（R3）和Lys-128（R2）特异性识别。相比之下，根据我们对完整DNA结合结构域（R1R2R3）的DNA复合物的核磁共振研究，R1与DNA没有特异性相互作用。
