摘要
测定了在第１１９位的天门冬氨酸被天门冬酰胺取代了的Ｃ－Ｈａ－Ｒａｓ的特异性。调节性的ＧＴＰ酶（三磷酸鸟苷酸酶）家族中的许多成员均有保守的ＮＫＸＤ顺序模式。第１１９位天门冬氨酸即是这一保守顺序模式中的一个残基。本研究发现Ｄ１１９Ｎ突变使Ｈａ－Ｒａｓ的核苷酸特异性从鸟嘌呤更改为黄嘌呤。此观察结果直接支持了下列结论：在天门冬氨酸残基的侧链和鸟嘌呤环之间的氢键形成对于核苷酸的结合的特异性起了最重要的。
We examined C Ha Ras harboring as aspartate to asparagine substitution at position 119(mutationD119N).The Asp-119 is part of the conserved NK×D motif shared by members of the regulatory GTPase family.This asparagine residue has been proposed to participate in direct bonding to the guanine ring and to determine the guanine-nuanine to xanthine,as observation that directly supports the essential role of hydrogen bonding between the side chain of the aspartic acid reidue and the guanine ring in nucleotide binding specificity.
出处
《郑州粮食学院学报》
1998年第4期1-9,共9页
Journal of Zhengzhou Institute of Technology
