Table 4.

Differential non-bond interaction of D121A variant between wild and mutant states

Wild [D121]	Mutant [A121]	Non-bond interaction type	Distance (A°)a
ARG111:ASP121	---	Salt bridge	1.95
ARG133:ASP121	---	Salt bridge	2.69
LYS109:ASP121	LYS109:ASP121	Strong H. bond	1.95
ARG111:ASP121	---	Strong H. bond	1.82
ASP121:LYS109	ASP121:LYS109	Strong H. bond	1.96

^aUnder steric bump; VDW fraction = 0.70; max. dist. of strong H. bond = 3.40; max. dist. of weak H. bonds = 3.8; max. dist. of the salt bridge = 4.0