Table 1.

Data Collection and Structural Refinement Statistics

PNP Mutant	His257Gly		His257Phe		His257Asp
Inhibitor	DADMe	ImmH	DADMe	ImmH	DADMe	ImmH
Ion	SO4	PO4	SO4	PO4	SO4	PO4
PDB ID	2A0W	2OC9	2A0X	2ON6	2A0Y	2OC4
Space group	R32	R32	R32	R32	R32	R32
Unit cell (Å)
a	141.881	142.441	141.764	143.011	142.467	143.386
b	141.881	142.441	141.764	143.011	142.467	143.386
c	166.399	168.765	166.172	168.324	166.029	168.457
	Data Collection
Resolution (Å)	50-2.28	30-2.60	50-2.28	30-2.50	50-2.28	30-2.60
No. of reflections total	267,740	128,876	265,893	151,918	262,079	142,541
unique	29,413	19,978	29,401	21,634	29,445	20,554
Completeness (%)	99.9(99.9)	97.2 (75.8)	99.9(100)	94.5(83.3)	99.9 (99.6)	99.3(94.6)
Rmerge (%)	4.6 (19.6)	6.9(39.9)	6.2 (36.4)	6.6(37.8)	5.1 (56.4)	7.1(55.1)
	Structural Refinement
Rcryst (%)	23.3	19.4	22.7	20.5	24.3	20.0
Rfree(%)	25.4	24.0	25.1	24.6	26.7	24.7
No. of amino acids	282	284	282	286	282	286
No. of ligands	1 DADMe	1 ImmH	1 DADMe	1 ImmH	1 DADMe	1 ImmH
	2 SO4	1 PO4	2 SO4	1 PO4	3 SO4	1 PO4
No. of water	79	48	60	50	46	53
	RMS Deviations
bond (Å)	0.007	0.024	0.007	0.022	0.007	0.029
angle (deg)	1.33	2.2	1.33	2.14	1.31	2.62
	Ramachandran Plot
most favor regions	89.5	87.6	90.8	88.7	87.9	84
add. allowed	10.1	10.7	8.8	10.5	11.7	13.9
gen. allowed	0.0	1.3	0.0	0.4	0.0	1.7
disallowed	0.4	0.4	0.4	0.4	0.4	0.4