title: Calcium binding sites in tomato bushy stunt virus visualized by Laue crystallography.
abstract: We have collected Laue diffraction data from crystals of tomato bushy stunt virus using the full white X-ray spectrum from the wiggler magnet of the Synchrotron Radiation Source at Daresbury, U.K. A single 24 second exposure of a crystal soaked in EDTA yielded a data set that was 90% complete between 6 and 3.5 A resolution. A large proportion of the data could be measured using an overlap deconvolution routine to separate spatially overlapping reflections in the dense Laue photograph. Reflections with I greater than 2 sigma I (40% of the data set) were subjected to wavelength normalization. A difference Fourier map between these reflections and a monochromatic native set showed, after icosahedral averaging, the three pairs of Ca2+ binding sites related by quasi-symmetry and the movement of a liganding loop in the protein at the A/C subunit interface. The extent and quality of the data obtained from a single Laue photograph of this virus were thus sufficient to detect clearly such small structural alterations. In a second experiment, a Laue photograph was taken from a crystal that was soaked first in EDTA and then in GdCl3. A difference Fourier map between this Laue data set and the Laue data set from the EDTA-soaked crystal showed clearly the Gd3+ sites in the capsid, demonstrating that the Laue technique is a reliable and efficient means for data collection with virus crystals.
authors.affiliation: SERC Daresbury Laboratory, Warrington, U.K.
authors.forename: J W
authors.initials: JW
authors.lastname: Campbell
authors.forename: I J
authors.initials: IJ
authors.lastname: Clifton
authors.forename: T J
authors.initials: TJ
authors.lastname: Greenhough
authors.forename: J
authors.initials: J
authors.lastname: Hajdu
authors.forename: S C
authors.initials: SC
authors.lastname: Harrison
authors.forename: R C
authors.initials: RC
authors.lastname: Liddington
authors.forename: A K
authors.initials: AK
authors.lastname: Shrive
mesh_terms: D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D005583:Fourier Analysis; D010942:Plant Viruses / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D002118:Calcium