EVIDENCE FOR THE ROLE OF SOLVATED METAL HYDROXIDE IN THE HAMMERHEAD CLEAVAGE MECHANISM

被引:312
作者
DAHM, SC [1 ]
DERRICK, WB [1 ]
UHLENBECK, OC [1 ]
机构
[1] UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA
关键词
D O I
10.1021/bi00211a013
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The log of the rate of the chemical step of hammerhead cleavage in Mg2+ increases linearly with pH between pH 5.7 and 8.9. A slope of approximately 1 indicates that a single deprotonation is required for cleavage. Hammerhead pH-rate profiles with Ca2+, Mn2+, Co2+, and Cd2+ correlate well with the pK(a)'s of these ions in water. This relationship between the pK(a)'s and the pH-rate profile suggests that a metal hydroxide bound to the hammerhead RNA acts as the base in the cleavage mechanism.
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页码:13040 / 13045
页数:6
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