A focusing Weissenberg camera with multi-layer-line screens for macromolecular crystallography

Abstract

A conventional Weissenberg camera [Weissenberg (1924). Z. Phys. 23,[229][230][231][232][233][234][235][236][237][238] has been modified for macromolecular crystallography. This camera system consists of a doubly bent LiF monochromator, a newly designed Weissenberg goniometer with multi-layerline screens and its controller. The camera is useful for recording many reflections up to high resolution on a film with high signal-to-background ratio from a crystal with large unit-cell dimensions without losing any of the diffracted beams by screens. The resulting photograph is very easy to index, and the ratio of partially recorded reflections to fully recorded reflections decreases in comparison with an oscillation camera. The multi-layer-line screens are especially practical with a continuous X-ray beam such as synchrotron radiation where both wavelength and band pass can be selected properly. The preparation of a point-focusing monochromator from a single crystal of LiF is described, and the recording of anomalous dispersion profiles is discussed.

Time‐resolved protein crystallography

“…The major disadvantage of conventional methods is the long time scale required for data collection, which limits the studies to those of stable structures, but new developments have shortened these times. Using the giant Weisenberg camera developed by N. Sakabe at the Photon Factory in Japan (Sakabe, 1983), J. Hajdu reported data collection to 1.5 A resolution for ribulose-l,5-bisphosphate carboxylase/oxygenase with exposure times less than 20 min (total data collection time was 2 h) (Andersson et al, 1991). This is an extraordinary achievement for one of the largest proteins under crystallographic analysis (molecular weight of the hexadecamer 550,000).…”

Structure of Holo-glyceraldehyde-3-phosphate Dehydrogenase fromPalinurus versicolorRefined at 2 Å Resolution

“…These three residues have well de®ned electron densities. The unfavorable dihedral angles of these residues have been observed in other GAPDH structures (Skarzynski et al, 1987;Due  e et al, 1996).…”

“…The data set was collected at the BL6A2 station of the KEK photon factory in Japan with a synchrotron radiation imaging-plate Weissenberg camera system (Sakabe, 1983) at a temperature of 7 . The rotation axis of a + b and a short wavelength of 1.00 A Ê were used to reduce the absorption error.…”

“…The enzyme, consisting of four identical subunits, is allosteric and shows a variety of cooperative properties. GAPDH structures were ®rst determined for the enzymes from lobster (Homarus americanus) muscle, and then for that from the moderate thermophile Bacillus stearothermophilus in several conformational states (Moras et al, 1975;Murthy et al, 1980;Skarzynski et al, 1987;Skarzynski & Wonacott, 1988). In addition, there are several crystallographic investigations for enzymes from other species such as human muscle (Mercer et al, 1976), Bacillus coagulans (Grif®th et al, 1983), Trypanosoma brucei (Vellieux et al, 1993), Thermotoga maritima (Korndorfer et al, 1995), Thermus aquaticus (Tanner et al, 1996), and E. coli (Due  e et al, 1996).…”

Quantitative Analysis of Synchrotron Laue Diffraction Patterns in Macromolecular Crystallography

“…Even for a tiny protein crystal (for example, a 150 × 50 × 50 pm crystal ofphotoactive yellow protein), Laue exposure times in the 20-100 ms range are adequate to get strong diffraction data from a dipole source on a second-generation synchrotron such as the National Synchrotron Light Source (NSLS; Moffat, Chen, Ng, McRee & Getzoff, 1992). Monochromatic techniques, such as conventional oscillation and, more recently, the Weissenberg technique (Sakabe, 1983(Sakabe, , 1991 still require exposure times greater than 100 s in total, at least, for a data set. For picosecond time resolution, it is impossible to collect data by monochromatic methods.…”