3CMX

Mechanism of homologous recombination from the RecA-ssDNA/dsDNA structures

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	APS BEAMLINE 24-ID-C
Synchrotron site	APS
Beamline	24-ID-C
Collection date	2007-02-01
Spacegroup name	P 21 21 2
Unit cell lengths	159.000, 300.500, 80.100
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	40.000 - 3.400
R-factor	0.239
Rwork	0.238
R-free	0.25600
Structure solution method	MOLECULAR REPLACEMENT
RMSD bond length	0.009
RMSD bond angle	1.186
Refinement software	REFMAC (5.3.0036)

Data quality characteristics

	Overall
Low resolution limit [Å]	40.000
High resolution limit [Å]	3.400
Number of reflections	49365

Crystallization Conditions

crystal ID	method	pH	temperature	details
1		8		RecA5 fusion protein was incubated with a 3-fold molar excess of ssDNA in the original protein buffer supplemented with 2 mM ADP, 10 mM MgCl2 and 8 mM AlF4, pH 6.0. Crystals of the RecA5-(ADP-AlF4-Mg)5-(dT)15 complex were grown from 50 mM Tris-Cl, 9% (w/v) PVP K15, 32% (v/v) MPD, 10 mM DTT, pH 8.0. RecA5-(ADP-AlF4-Mg)5-(dT)15-(dA)12 complex were obtained by soaking the RecA5-(ADP-AlF4-Mg)5-(dT)15 crystals in a 0.2 mM solution of the complementary (dA)12 oligonucleotide in 25 mM Tris-Cl, 9% (w/v) PVP K15, 32% (v/v) MPD, 2 mM ADP, 8 mM AlF4, and 10 mM MgCl2 for 4 hr.

Crystallization Reagents

ID	crystal ID	solution ID	reagent name	concentration	details
1	1	1	ADP
10	1	2	MPD
11	1	2	DTT
12	1	3	25 mM Tris-Cl
13	1	3	PVP K15
14	1	3	MPD
15	1	3	ADP
16	1	3	AlF4
17	1	3	MgCl2
2	1	1	MgCl2
3	1	1	AlF4
4	1	1	50 mM Tris-Cl
5	1	1	PVP K1
6	1	1	MPD
7	1	1	DTT
8	1	2	50 mM Tris-Cl
9	1	2	PVP K1