Open AccessPushing the limits of sulfur SAD phasing: de novo structure solution of the N‐terminal domain of the ectodomain of HCV E1
Author(s) -
El Omari Kamel,
Iourin Oleg,
Kadlec Jan,
Fearn Richard,
Hall David R.,
Harlos Karl,
Grimes Jonathan M.,
Stuart David I.
Publication year - 2014
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s139900471401339x
Subject(s) - ectodomain , phaser , substructure , resolution (logic) , wavelength , diffraction , crystallography , chemistry , optics , physics , algorithm , materials science , computer science , biochemistry , receptor , structural engineering , artificial intelligence , engineering
Single‐wavelength anomalous dispersion of S atoms (S‐SAD) is an elegant phasing method to determine crystal structures that does not require heavy‐atom incorporation or selenomethionine derivatization. Nevertheless, this technique has been limited by the paucity of the signal at the usual X‐ray wavelengths, requiring very accurate measurement of the anomalous differences. Here, the data collection and structure solution of the N‐terminal domain of the ectodomain of HCV E1 from crystals that diffracted very weakly is reported. By combining the data from 32 crystals, it was possible to solve the sulfur substructure and calculate initial maps at 7 Å resolution, and after density modication and phase extension using a higher resolution native data set to 3.5 Å resolution model building was achievable.