Experiment: 9XKT

Crystal structure of the complex of the GH16 carrageenase SfGH16 from Saccharicrinis fermentans with an oligotetrasaccharide of iota-carrageenan

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
in silico model	AlphaFold

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP		290	0.1 M Sodium citrate tribasic dihydrate pH 5.60, 20% v/v 2-Propanol

Crystal Properties
Matthews coefficient	Solvent content
2.55	51.85

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 57.692	α = 90
b = 67.878	β = 90
c = 84.465	γ = 90

Symmetry
Space Group	P 21 21 21

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	PIXEL	DECTRIS PILATUS3 6M		2025-10-04	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRF BEAMLINE BL18U1	0.987	SSRF	BL18U1

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	CC (Half)	Net I Over Average Sigma (I)	Redundancy	Number Reflections (All)	Number Reflections (Observed)	Observed Criterion Sigma (F)	Observed Criterion Sigma (I)	B (Isotropic) From Wilson Plot
1	1.44	52.91	100	0.081	0.092	0.999	18.2	8.5		61087

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.44	1.52			0.654	0.747	3.1

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	FREE R-VALUE	1.44	35.86	58468	1908	95.79	0.1489	0.148	0.1465	0.1753	0.1739

Temperature Factor Modeling
Anisotropic B[1][1]	Anisotropic B[1][2]	Anisotropic B[1][3]	Anisotropic B[2][2]	Anisotropic B[2][3]	Anisotropic B[3][3]

RMS Deviations
Key	Refinement Restraint Deviation
f_dihedral_angle_d	7.799
f_angle_d	1.064
f_chiral_restr	0.092
f_plane_restr	0.01
f_bond_d	0.006

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2117
Nucleic Acid Atoms
Solvent Atoms	481
Heterogen Atoms	59

Software

Software
Software Name	Purpose
PHENIX	refinement
PDB_EXTRACT	data extraction
autoPROC	data processing
Aimless	data scaling
PHASER	phasing