Ueda H, Iyo H, Doi M, Inoue M, Ishida T, Morioka H, Tanaka T, Nishikawa S, Uesugi S
Osaka University of Pharmaceutical Sciences, Japan.
FEBS Lett. 1991 Mar 25;280(2):207-10. doi: 10.1016/0014-5793(91)80294-d.
Four mutants of the human cap binding protein (hCBP), in which Trp-102, Glu-103, Asp-104 or Glu-105 was changed to the aliphatic Leu or Ala, were prepared, and their cap binding abilities were examined. Cap binding abilities of two mutants, W102L (Trp-102----Leu) and E105A (Glu-105----Ala), were significantly decreased in comparison with the wild-type hCBP. This result suggests that Trp-102 and Glu-105 are both necessary for the cap binding, and the most probable binding mode with the m7G of cap structure is the combination of the stacking by Trp-102 and the hydrogen-bond pairing by Glu-105, as was already proposed from the model studies.
制备了人帽结合蛋白（hCBP）的四个突变体，其中色氨酸-102、谷氨酸-103、天冬氨酸-104或谷氨酸-105被替换为脂肪族亮氨酸或丙氨酸，并检测了它们的帽结合能力。与野生型hCBP相比，两个突变体W102L（色氨酸-102→亮氨酸）和E105A（谷氨酸-105→丙氨酸）的帽结合能力显著降低。该结果表明，色氨酸-102和谷氨酸-105对于帽结合都是必需的，并且与帽结构的m7G最可能的结合模式是色氨酸-102的堆积作用与谷氨酸-105的氢键配对作用相结合，正如之前模型研究中所提出的那样。
