help with this:

Histone deacetylases $($HDACs$)$ are zinc$-$dependent enzymes that catalyse the conversion of

acetyllysine to lysine.

a$)$ Propose the mechanism for the HDAC$-$catalysed reaction.

b$)$ What is the role of zinc ion in HDAC catalysis?

c$)$ Draw the pH$-$activity profile for HDAC$-$catalysed conversion of acetyllysine to lysine.

Explain.

d$)$ Suggest two acetyllysine analogues that are substrates for HDACs. One should be a better

substrate than acetyllysine, whereas the other one should be a worse substrate than

acetyllysine. Explain.

e$)$ Mutations in the HDAC sequence could lead to a loss of the catalytic function. Which

mutations are problematic?

f$)$ Lysine acetylation is a reversible reaction using acetyl$-$CoA as a co$-$substrate. Which

coenzymes are required for synthesis of acetyl$-$CoA in nature? Propose the mechanism.