Table 1.

Data collection and refinement statistics

Data collection
Resolution (Å)	50–2.7
No. observations	65,855
No. unique	26,564
Redundancy*	2.8 (2.4)
% Complete	92.5 (73.7)
Rsym†	0.056 (0.195)
No. of reflections Rwork (Rfree)	24,727 (1,322)
Rwork‡ (Rfree)	24.2 (29.5)
rmsd§ bonds (Å)	0.007
rmsd angles (°)	1.35
Overall avg. B-factor (Å2)	52.3
rmsd¶ B (main chain, Å2)	2.8
smsd¶ B (side chain, Å2)	3.7
No. protein atoms	5,627
No. of NAG molecules	2
No. water molecules	48
Ramachandran plot quality
Most favored (%)	83.2
Additionally favored (%)	15.8
Generously allowed (%)	1.0
Disallowed (%)	0.0

NAG, N-acetylglucosamine. 

^*Parentheses denote statistics in the highest resolution shell of 2.8–2.7 Å. 

^† R_sym = (Σ|I(i) − 〈I(h)〉|)/(ΣI(i)) where I(i) is the ith observation of the intensity of a reflection with indices h, k, l and 〈I(h)〉 is the average intensity of all symmetry equivalent measurements of that reflection. 

^‡ R_work = Σ|F_obs(h) − F_calc(h)|/Σ|F_obs(h)| where F_obs(h) and F_calc(h) are the observed and calculated structure factor amplitudes, respectively. R_free is calculated as R_work but for 5% of the data excluded from refinement. 

^§ rms deviations (rmsd) in bond lengths and angles are the deviations from ideal values. 

^¶ rmsd for bonded atoms.