Table 1.

Crystallographicdataandrefinementstatistic

Data collection	CPT:2-N-Ac-Cm	CPT:p-NH2-Cm
Resolution [Å]	3.1	2.9
Total data	229,617	370,300
Unique data	12,472	14,719
Overall completeness	0.98	0.951
Completeness (last shell)	0.906	0.593
F2 > 3σ(F2) [%]	84.6	77.8
Ramerge (overall)	0.167	0.051
Ramerge (last shell)	0.323	0.298
Average F2/σ(F2)	13.9	48.8
Crystallographic refinement
Number of reflections	10,677	14,463
Final model parameters
Number of amino acid residues	178	178
Number of protein atoms	1320	1320
Number of solvent molecules	81	92
Resolution range [Å]	42 - 3.1	45 - 2.9
R-factorb (overall)	0.226	0.278
R-factorb (last shell)	0.336	0.438
Rcfree (overall)	0.256	0.297
Rcfree (last shell)	0.332	0.463
Average main-chain B-factor [Å2]	40.2	60.4
Average side-chain B-factor [Å2]	51.4	67.7
Average water molecule B-factor [Å2]	35.29	56.4
Average ligand B-factor [Å2]	72.8	79.7
r.m.s. deviations from ideal geometry
Covalent bond lengths [Å]	0.006	0.008
Bond angles [˚]	1.1	1.3

^c The free R-factor is a cross-validation residual calculated by using 5% of the native data which were randomly chosen and excluded from the refinement.