Talk:ADP-ribosylation

I propose that the mechanism provided in this page be modified - it appears that the carboxy groups rather than the side chains of the glutamate residues are engaged in contacts with the Arg and the ribose (Step 2).

Kpuvar25 (talk) 17:48, 19 December 2019 (UTC)[reply] The mechanistic figure and associated text does not seem to be factual, or is at least dubious.

Furthermore, investigation into this class of enzymes (i.e., EXE motif ADP ribosyltransferases) suggests that the glutamic acid residues are "...thought to stabilize the furanosyl oxocarbenium intermediate" (Cohen and Chang, Nat Chem Biol., 2018 Feb 14).

Furthermore, the glutamic acid side chain carboxyl groups seem to be mediating catalysis, not the amino acid carboxyl group--the latter would not be present due to being part of the peptide backbone and would therefore exist as a peptide bond.

The text and mechanistic figure are thus in need of proper citation, or a removal of the proposed mechanism altogether.Hakuran90 (talk) 20:05, 25 November 2020 (UTC)[reply] If the mechanism isn’t to your liking, draw a new figure and replace it.