1.7.1.13	C190A	complete loss of activity	724767	
1.7.1.13	C190A	mutation in catalytic residue, no evidence of covalent binding of substrate preQ0. Mutant displays proton uptake	742900	
1.7.1.13	C190A	the mutation annihilates preQ0 covalent binding and largely disrupts the nitrile-to-amine reductase activity	764418	
1.7.1.13	C190S	the mutation annihilates preQ0 covalent binding and largely disrupts the nitrile-to-amine reductase activity	764418	
1.7.1.13	C99A	mutant does not compromise enzyme activity. Contrary to wild-type, peroxide-induced inactivation is irreversible	-, 742061	
1.7.1.13	C99S	mutant does not compromise enzyme activity. Contrary to wild-type, peroxide-induced inactivation is irreversible	-, 742061	
1.7.1.13	D197A	the variant does not take up protons in conjunction with preQ0 binding	764418	
1.7.1.13	D197H	the variant recovers proton uptake to a level almost analogous to that seen with the wildtype enzyme	764418	
1.7.1.13	D197N	complete loss of activity	724767	
1.7.1.13	E230Q	about 4% of wild-type activity for natural substrate 2-amino-5-cyanopyrrolo[2,3-d]pyrimidin-4-one	724767