1Q4N

Structural studies of Phe256Trp of human salivary alpha-amylase: implications for the role of a conserved water molecule and its associated chain in enzyme activity

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	9		MPD, Calcium Chloride, Tris, pH 9.00, VAPOR DIFFUSION, HANGING DROP, temperature 100K

Crystal Properties
Matthews coefficient	Solvent content
2.32	46.94

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 51.9	α = 90
b = 74.2	β = 90
c = 134.82	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	IMAGE PLATE	MAR scanner 345 mm plate	MIRRORS	2001-12-01	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU300	1.5418

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	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	2.07	41.1	94.5	0.06	13	3	89732	30610	1	1	28

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	2.07	2.14	60

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	PDB ENTRY 1MFV	2.07	41.17	30610	29010	1551	94.04	0.15874	0.15623	0.20585	RANDOM	24.753

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
r_dihedral_angle_1_deg	6.949
r_scangle_it	3.477
r_scbond_it	2.225
r_angle_refined_deg	1.547
r_mcangle_it	1.432
r_angle_other_deg	0.92
r_mcbond_it	0.791
r_symmetry_vdw_other	0.299
r_nbd_other	0.246
r_nbd_refined	0.199
r_xyhbond_nbd_refined	0.165
r_symmetry_hbond_refined	0.164
r_chiral_restr	0.098
r_nbtor_other	0.087
r_symmetry_vdw_refined	0.074
r_bond_refined_d	0.016
r_gen_planes_refined	0.007
r_gen_planes_other	0.006
r_bond_other_d	0.002
r_dihedral_angle_2_deg
r_xyhbond_nbd_other
r_symmetry_hbond_other
r_rigid_bond_restr
r_sphericity_free
r_sphericity_bonded

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3949
Nucleic Acid Atoms
Solvent Atoms	324
Heterogen Atoms	13

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
REFMAC	refinement
AMoRE	phasing