Table 1.

Crystallographic data collection and structure refinement statistics. Values in parentheses correspond to the highest resolution shell.

	BR_20C (5VN7)		BR_4C (5VN9)
Data collection
Wavelength (Å)	1.033		1.033
Number of crystals	4		5
Resolution range (Å)	28.52 - 2.70 (2.80 - 2.70)		28.34 - 2.59 (2.69 - 2.59)
Space group	R 3		P 21
Unit cell, a b c (Å) α β γ (°)	107.05 107.05 149.86 90 90 120		50.07 109.63 56.56 90 116.3 90
Total reflections	51,454 (4,126)		40,533 (1,396)
Unique reflections	17,181 (1,716)		15,034 (833)
Multiplicity	3.0 (2.4)		2.7 (1.7)
Completeness (%)	97 (96)		90 (49)
Mean I/sigma(I)	7.4 (1.8)		5.3 (1.7)
Wilson B-factor (Å2)	52.8		46.5
R-merge	0.151 (0.645)		0.143 (0.317)
CC1/2	0.988 (0.476)		0.987 (0.76)
Refinement
R-work/ R-free	0.196/0.225		0.223/0.265
Clashscore	4.4		5.5
	A	B	A	B
Number of non-hydrogen atoms	1,748	1,740	1,766	1,746
protein	1,728	1,720	1,735	1,720
retinal	20	20	20	20
water	0	0	11	6
Average B-factor	51.8	67.5	39.3	36.4
protein	51.9	67.5	39.4	36.5
retinal	42.5	49.5	35.4	33.2
water	–	–	38.1	33.7
RMS bonds (Å)	0.004		0.003
RMS angles (°)	0.64		0.58
	A	B	A	B
Ramachandran favored (%)	99.1	97.3	98.6	98.6
Ramachandran allowed (%)	0.9	2.7	1.4	1.4
Ramachandran outliers (%)	0	0	0	0