TABLE 1.

Crystallographic data processing and refinement statistics

	Ca2+-bound derCD23	Ca2+-free derCD23	E249A derCD23	S252A derCD23	D258A derCD23	D270A derCD23	Ca2+-bound derCD23-Fcϵ3-4
PDB accession code	4G9A	4G96	4GI0	4GJ0	4GJX	4GK1	4GKO
Data processing statistics
Beamline	DLS I03	Daresbury 14.1	DLS I03	DLS I02	DLS I03	DLS I02	DLS I04-1
Wavelength	0.9763 Å	1.4880 Å	0.9763 Å	0.9795 Å	0.9763 Å	0.9795 Å	0.9173 Å
Processing software	HKL2000	HKL2000	HKL2000	HKL2000	MOSFLM	HKL2000	MOSFLM
Space group	P1	P1	P4122	P1	P65	P212121	P212121
Unit cell parameters	a = 54.24 Å	a = 52.40 Å	a = 63.32 Å	a = 52.50 Å	a = 90.97 Å	a = 73.78 Å	a = 62.83 Å
	b = 53.71°	b = 56.73°	b = 63.32°	b = 56.87°	b = 90.97°	b = 109.11°	b = 110.13°
	c = 56.64°	c = 62.20°	c = 261.42°	c = 62.68°	c = 351.68°	c = 139.00°	c = 367.41°
	α = 112.92°	α = 68.49°		α = 68.06°
	β = 88.53°	β = 88.16°		β = 88.23°
	γ = 114.96°	γ = 73.40°		γ = 73.53°
No. of mol/a.u.	4	4	3	4	8	7	9
Resolution rangea	50.0 to 2.00 Å (2.07 to 2.00 Å)	57.2 to 2.25 Å (2.37 to 2.25 Å)	65.4 to 2.27 Å (2.40 to 2.27 Å)	50.0 to 1.95 Å (2.02 to 1.95 Å)	58.67 to 2.80 Å (2.95 to 2.80 Å)	50.0 to 2.25 Å (2.33 to 2.25 Å)	73.5 to 3.30 Å (3.48 to 3.30 Å)
Observations	139,591	82,009	323,278	97,210	133,827	382,280	157,453
Unique reflections	34,591	28,279	25,713	45,157	36,967	54,601	33,757
Average redundancy	4.0 (4.1)	2.9 (2.9)	12.6 (13.0)	2.2 (2.1)	3.6 (3.5)	7.0 (6.7)	4.7 (4.9)
Completeness	97.9% (96.9%)	94.6% (86.7%)	100% (100%)	97.1% (93.7%)	91.6% (94.3%)	99.7% (99.5%)	84.0% (86.3%)
Wilson B-factor	20.0 Å2	42.5 Å2	50.7 Å2	29.9 Å2	41.5 Å2	37.8 Å2	92.9 Å2
I/σ(I)	20.5 (4.6)	10.8 (3.6)	12.9 (2.3)	20.0 (2.0)	7.0 (1.9)	34.0 (4.0)	5.1 (1.4)
Rmergeb/Rp.i.m.c	0.096b (0.406)	0.065b (0.226)	0.020b (0.359)	0.049b (0.369)	0.081c (0.400)	0.078b (0.463)	0.089c (0.501)
Refinement statistics
Resolution range	38.8 to 2.00 Å	39.4 to 2.25 Å	65.6 to 2.27 Å	31.3 to 1.95 Å	78.8 to 2.80 Å	43.9 to 2.24 Å	183.7 to 3.30 Å
Total no. of reflections	34,538	26,856	24,325	45,141	35,034	54,533	31,969
No. of working reflections	32,806	25,433	23,019	42,853	33,200	51,765	30,285
No. of test reflections	1732	1423	1306	2288	1834	2768	1684
R factord	0.155	0.176	0.207	0.169	0.210	0.183	0.275
Rworking	0.152	0.173	0.205	0.166	0.208	0.181	0.272
Rfree	0.205	0.236	0.251	0.212	0.251	0.226	0.312
No. of atoms	4,697	4,571	3,328	4,710	8,810	8,120	16,217
Protein	4,271	4,273	3,202	4,257	8,635	7,452	15,823
Otherse	426	298	126	453	175	668	394
r.m.s. bond length deviation	0.006 Å	0.017 Å	0.010 Å	0.007 Å	0.006 Å	0.006 Å	0.020 Å
r.m.s. bond angle deviation	0.963°	1.944°	1.375°	1.031°	0.987°	0.937°	1.963°
Mean B factor	25.7 Å2	41.3 Å2	31.6 Å2	40.4 Å2	51.0 Å2	43.5 Å2	150.5 Å2
Main chain	22.3	39.1	30.5	37.0	50.5	40.8	148.8
Side chain	29.1	43.6	32.6	43.7	51.5	46.1	152.1
Otherse	35.5	44.4	46.3	48.2	32.5	53.5	163.6
r.m.s. backbone B factor deviationf	2.4	2.0	1.1	2.9	1.0	2.3	3.5
Ramachandran statisticsg
Favored	96.2%	94.1%	93.7%	96.0%	95.3%	95.5%	90.9%
Allowed	100%	99%	99.5%	99.8%	99.9%	100%	99.1%
Outliers	0%	1%	0.5%	0.2%	0.1%	0%	0.9%

^a Values in parentheses are for the outer resolution shell.

^b R_merge = Σ|I_obs − 〈I〉|/Σ〈I〉.

^c R_p.i.m. (precision-indicating merging R-factor) = Σ_hkl(1/(N − 1))^1/2 Σ_i|I_i(hkl) − I(−h−k−l)|/Σ_hklΣ_iI_i(hkl) (49).

^d R factor = Σ_hkl‖F_o(hkl)| − |F_c(hkl)‖/Σ_hkl|F_o(hkl)|.

^e Ca²⁺ ions, carbohydrate, water molecules, SO₄²⁻ ions and glycerol.

^f Root mean square (r.m.s.) deviation between B-factors for bonded main chain atoms.

^g Data are defined by MolProbity (50).