Table 1.

Summary of crystallographic data

	YQR-CO	YQR⋯CO*
Data statistics
Temperature, K	100	20
Unit cell (Å) in P6	a = b = 90.49, c = 45.28	a = b = 90.61, c = 45.33
Resolution, Å	19.6–1.4	18.0–1.4
# Reflection (total/last shell)	143,218/15,373	136,182/14,395
# Unique refl. (total/last shell)	40,518/7,138	41,213/7,686
Completeness (total/last shell), %	96.5/91.4	98.5/99.1
I/σ (total/last shell)	19.8/5.8	19.8/5.3
Rsym (total/last shell), %	3.6/12.5	3.6/11.1
Refinements
Resolution, Å	19.6–1.4	18.0–1.4
# Water molecules	259	266
R/Rfree,* %	12.9/15.4	13.2/16.6
rms bond/over all coord. [Å], ESU or ML based‡	0.014/0.024	0.015/0.025
Biso overall/Biso water [Å2]	14.0/27.0	14.8/28.0
B CO: [Å2]	C: 8.5/O: 14.6	13.6/21.4†

*The same set of 5% randomly chosen reflections was used for calculation of R_free. 

^†The diffraction data do not allow assigning the carbon and oxygen atoms, respectively. 

^‡ESU, estimated standard uncertainty; ML, maximum likelihood