3BIR

DISECTING HISTIDINE INTERACTIONS IN RIBONUCLEASE T1 BY ASN AND GLN SUBSTITUTIONS

X-RAY DIFFRACTION

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Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1BIR	PDB ENTRY 1BIR

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1		4.2		VAPOR DIFFUSION, NAOAC PH 4.2, 20 MG/ML PROTEIN, 45 % MPD 2.5 MM CACL2, 20 MM GPS

Crystal Properties
Matthews coefficient	Solvent content
2.13	42.2

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 40.16	α = 90
b = 46.88	β = 90
c = 50.07	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	293	IMAGE PLATE	MARRESEARCH	DUAL SLITS	1995-11-06	M

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

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Sym 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	2.3	10	94	0.107	5.5	5		4313		3	14.2

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	2.3	2.38	50		0.239	3.1	4.2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	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 1BIR	1.8	10	8600	475	94	0.192	0.192	0.237	RANDOM	15.3

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
x_dihedral_angle_d	26.2
x_scangle_it	3.71
x_improper_angle_d	2.82
x_scbond_it	2.72
x_angle_deg	2.5
x_mcangle_it	2.11
x_mcbond_it	1.42
x_bond_d	0.028
x_bond_d_na
x_bond_d_prot
x_angle_d
x_angle_d_na
x_angle_d_prot
x_angle_deg_na
x_angle_deg_prot
x_dihedral_angle_d_na
x_dihedral_angle_d_prot
x_improper_angle_d_na
x_improper_angle_d_prot

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	789
Nucleic Acid Atoms	29
Solvent Atoms	384
Heterogen Atoms

Software

Software
Software Name	Purpose
MOSFLM	data reduction
ROTAVATA	data reduction
AMoRE	phasing
X-PLOR	refinement
CCP4	data scaling