Sandbox Reserved 774: Difference between revisions
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[[Image:Hpa2_Active_Sites.jpg]] [[Image:Hpa2 Secondary Structure.jpg]] | [[Image:Hpa2_Active_Sites.jpg]] [[Image:Hpa2 Secondary Structure.jpg]] | ||
=Mechanism= | =Mechanism= | ||
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==Chemical Mechanism== | ==Chemical Mechanism== | ||
After the formation of a ternary complex of acetyl-CoA, histone and enzyme, an active site base deprotonates lysin, which allows for direct attack of the N-e-lysine on the carbonyl carbon of acetyl-CoA. | After the formation of a ternary complex of acetyl-CoA, histone and enzyme, an active site base deprotonates lysin, which allows for direct attack of the N-e-lysine on the carbonyl carbon of acetyl-CoA. Additionally, without a histone acceptor, slow rates of enzyme auto-acetylation (7 x 10-4 s-1, or ~2500-fold slower than histone acetylation; kcat = 1.6 s-1) and of CoA formation (0.0021 s-1) were not consistent with a kinetically competent acetyl-enzyme intermediate. | ||
