Table 2. Summary of data-refinement statistics for native HpxW.

Resolution (Å)	2.7
No. of protein atoms	6380
No. of ligand atoms	0
No. of water atoms	0
Reflections in working set	37226
Reflections in test set	1964
R factor† (%)	25.7
R free ‡ (%)	29.8
R.m.s.d. from ideal
Bond lengths (Å)	0.008
Angles (°)	1.065
Average B factor (Å2)	47.9
Ramachandran plot
Favored (%)	94.98
Allowed (%)	4.44
Disallowed (%)	0.58

^† R factor = , where F _obs and F _calc are observed and calculated structure factors, respectively.

^‡For R _free the sum is extended over a subset of reflections (5%) that were excluded from all stages of refinement.