1.1.1.23 NAD+ - 1.1.1.23 NAD+ binding site structure 1.1.1.23 NAD+ amino acid residues contributing to NAD+ binding include Tyr129, Gly132, and Asn221 for phosphate binding, Gln193 and Asn221 for adenosine sugar binding, and Phe58, Gln193, and Tyr223 for adenine base binding 1.1.1.23 NAD+ the amine group is responsible of the substrate orientation by interacting with the Zn2+ while the overall stabilization of the cation changed between the unbound and bound forms 1.1.1.23 NAD+ the amine group is responsible of the substrate orientation by interacting with the Zn2+ while the overall stabilization of the cation changes between the unbound and bound forms