Table 1.

Crystallographic statistics

Data Collection
Data set	Tm$ SecA-SecYEG	Tm SecA-SecYEG	Bs SecA-Tm SecYE	Bs SecA-Aa SecYEG
Compound	Se-Met SecYEG	native	native	native
Resolution limit [Å]	4.5	5.7	6.2	7.5
Space group	P212121	P21	P65	P212121
Cell constants [Å]/[°]	101.6, 156.0,358.1	172.5, 102.5, 181.9	240.3,240.3, 179.5	146.4, 168.0, 187.7
(a, b, c, / α, β, γ)	90, 90, 90	90, 100.9, 90	90,90, 120	90,90, 90
Measured reflections	76164	39014	28484	6238
Unique reflections	34733	18704	13510	5416
Mean I/σ(I)	16.1 (2.0)#	16.5(1.5)	26.2 (2.5)	16.2(1.6)
Rsym (%)a	0.065 (0.85)	0.055 (0.87)	0.075 (>1.0)	0.072 (0.76)
Completeness (%)	97.7 (89.7)	93.3 (81.8)	100.0(100.0)	99.1 (99.8)
Redundancy	11.6 (8.8)	3.8 (2.5)	9.4 (9.0)	3.5(3.6)
SAD-Phasingb
FOM (from SOLVE)	0.25 (0.12)
FOM (post NCS averag.)	0.72 (0.27)
Refinement			Rigid body
Resolution range [Å]	15–4.5		15–6.2	15–7.5
NCSc	2	2	2	2
Rwork(%)‖	28.0		42.0	36.4
Rfree (%)¶	32.2		42.7	38.4
Number of Reflections
Total	32721		9176	4884
Rfree	3269		1012	532
Number of atomsd
Protein	21312
Nonprotein	62
Model geometry
r.m.s.d. bond length [Å]	0.0097
r.m.s.d. bond angle [°]	1.34
Average B-factor [Å2]
Main chain	374
Side chain	338
Ramachandran analvsise (for 1333 residues)
Most favored	65.3
Allowed	27.9
Generously allowed	5.3
Disallowed	1.5

^$Tm: T. maritima, Bs: B. subtilis, Aa: A. aeolicus

^#Values in parenthesis refer to the highest resolution shell.

^a$R_{sym}=\sum _{hkl}\sum _i\left|I_i\left(hkl\right)-I\left(hkl\right)\right|/\sum _{hkl}\sum _i\left|I_i\left(hkl\right)\right|$, where I(hkl) is the integrated intensity of the reflection.

^bFrom 11 selenium sites identified per SecA-SecYEG complex in the resolution range from 15 to 6 Å. NCS averaging included phase extension to 4.5 Å.

^cNumber of SecA-SecY complexes per ciystallographic asymmetric unit.

^dIn the asymmetric unit.

^eFor one SecA-SecYEG complex.

^‖$R_{\mathit{\text{work}}}=\left(\sum \left|F_o-F_c\right|\right)/\sum F_o$, where F_o and F_c are observed and calculated structure factors.

^¶Ten percent of the data were excluded from refinement to calculate R_free.