Dear All, Wish you all a very happy new year. In this new year working on a problem that I would like get your opinion.
Currently working on an enzyme that turnovers Coenzyme A (CoA)-conjugated substrate. I have determined the structure of the enzyme and the structure suggests to be a single domain protein. Based on the chemistry of the reaction and the position of the active site residues it seems that the CoA portion of the substrate will be out of the protein during catalysis. Both the monomeric architecture and the oligomeric (trimeric) assembly of the protein does not reveal a binding pocket. However, steady state kinetic expts suggest that the enzyme has preference towards CoA-conjugated substrate. The enzyme can turnover non-CoA-conjugated substrate but at a lower substrate specificity. I was wondering if anyone has encouneterd a similar problem or can shed any light about the possible interaction of CoA? Is it possible that the CoA induces macromolecular crowding or oligomerization whereby a binding pocket is created to accommodate CoA? Any suggestions or previously published references will be very helpful in this regard. Thanks for your time. Shiva
