Experiment: 9YZL

Isoreticular co-crystal of Replication Initiator Protein REPE54 and asymmetrical expanded duplex (31mer) containing the cognate REPE54 sequence, and additional T-A rich sequence with 5' terminal phosphates. Two copies of Even-skipped homeodomain loaded post-crystallization

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	7RVA
experimental model	PDB	1JGG

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	6.5	298	30mM Magnesium Acetate, 1.2M Lithium sulfate, 50mM MES pH 6.5. The crystal was crosslinked with 33mg/mL EDC overnight, and then looped into a solution of 15mM potassium chloride, 4mM calcium chloride, 10% glycerol, and 10mM Tris hydrochloride for 1 hour. The drop was then supplemented with 30 micromolar Even-skipped homeodomain

Crystal Properties
Matthews coefficient	Solvent content
4.52	72.81

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 73.365	α = 90
b = 120.285	β = 91.466
c = 134.401	γ = 90

Symmetry
Space Group	I 1 2 1

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 EIGER X 9M		2025-04-13	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	ALS BEAMLINE 8.2.1	1.0	ALS	8.2.1

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	Rpim 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	3.02	46.31	98.3	0.198	0.234	0.124	0.966	3.8	3.5		22518			86.65

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	Rpim I (All)	CC (Half)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	3.02	3.19	98.5		1.428	1.675	0.868	0.622	0.9	3.6

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	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	3.02	44.81	1.34	22418	2223	97.63	0.2836	0.2825	0.283	0.2942	0.2951	139.96

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	24.5879
f_angle_d	0.6035
f_chiral_restr	0.0415
f_plane_restr	0.0049
f_bond_d	0.0036

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2203
Nucleic Acid Atoms	1271
Solvent Atoms
Heterogen Atoms	2

Software

Software
Software Name	Purpose
PHENIX	refinement
XDS	data reduction
XSCALE	data scaling
PHASER	phasing
Coot	model building