How does GAP catalyze the GTPase reaction of Ras?: a computer simulation study

The way in which GTPase reaction of Ras is catalyzed by GAP is discussed based on a computer simulation study. Feasibility of the associative and dissociative mechanism in the GTPase reaction of Ras was explored. One conclusion is that the reaction is mostly likely to involve an associative mechanism. The effect of Arg 789 was seen to be associated with its direct interaction with the transition state charge distribution. The oncogenic effect of mutating Gln61 was explored.