Explicit treatment of spin labels in modeling of distance constraints from dipolar EPR and DEER.
Current SDSL-EPR methods allow measurement of dipolar distances in the 8-70 A range; however, the use of extrinsic probes complicates the interpretation of these distances in modeling macromolecular structure and conformational changes. The data presented here show that interprobe distances correlate only weakly with Cbeta-Cbeta distances, especially for distances that are on the order of the spin label tether lengths. Explicitly incorporating the spin label into the modeling process increases the experiment/model correlation 4-fold and reduces the distance error from 6 A to 3 A.
Biosystems Research Department, Sandia National Laboratories, Livermore, California, USA. klsale@sandia.gov
Ken
K
Sale
Likai
L
Song
Yi-Shiuan
YS
Liu
Eduardo
E
Perozo
Piotr
P
Fajer
D002244:Carbon / Q000737:chemistry; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D009010:Monte Carlo Method; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D013113:Spin Labels
D011506:Proteins; D013113:Spin Labels; D002244:Carbon