Skip to main content
. 2017 Aug 10;114(35):9343–9348. doi: 10.1073/pnas.1702201114

Table S2.

FRET efficiencies and distances determined from SecA37 FRET pairs on SecA–PhoA–SecYEG complex

Labeled site on SecA Labeled site on PhoA peptide portion of SecA–PhoA chimera
SecA37–AF647–PhoA PhoA2–AF488 PhoA22–AF488 PhoA37–AF488 PhoA45–AF488
R0*: 57 R0*: 58 R0*: 57 R0*: 60
fD = 0.40, fA = 0.58 fD = 0.70, fA = 0.88 fD = 0.72, fA = 1.00 fD = 0.68, fA = 0.80
EFRET Distance EFRET Distance EFRET Distance EFRET Distance
ADP and SecYEG 0.27 ± 0.003 67 ± 15 0.52 ± 0.02 56 ± 12 0.39 ± 0.03 62 ± 13 0.36 ± 0.03 66 ± 15
ATP-γS and SecYEG 0.20 ± 0.06 72 ± 16 0.42 ± 0.02 60 ± 13 0.32 ± 0.04 65 ± 14 0.21 ± 0.04 75 ± 16
*

R0 values given in angstroms were calculated as previously described (20).

The donor−acceptor distances (R) given in angstroms were calculated as described in SI Materials and Methods and consider the fractional labeling of the donor (fD) and acceptor (fA) in the doubly labeled complex. The larger error in the distances results from a consideration of the steady-state fluorescence anisotropy values of the dyes.

The FRET efficiency (EFRET) was calculated from the decrease of donor fluorescence intensity in the presence of the acceptor as described in SI Materials and Methods. The indicated error is determined from three independent measurements.