Compare base flipping between the Hha I methyltransferase in

Compare base flipping between the Hha I methyltransferase (intentional methylation) and the hUNG protein (human Uracil-N-glycosylase). Make sure your answer compares the enzymes on the following topics (you might just make a little table).

Where is the base physically when it is modified?

What happens to the orphan base and vacated site?

What is the base react with in the enzyme?

Is the binding sequence specific?

Does the enzyme engage the major or minor groove?

Is the base flipping reversible?

Solution

HhaI hUNG 1 where is th base physically located 5\'-GCGC-3\' (first Cin this recognition sequence) G-U mismatched pair 2 what happens to the orphan base and vacated site the enzyme provides hydrogen bonds to the orphan guanine the vacated site is replaced with a normal base by DNA polymerase 3 what is the base react within the enzyme Cys81 4 Is the binding sequence specific Yes No 5 Does the enzyme engage major groove or minor grove? major minor 6 base flipping reversible? irreversible reversible