title: Crystallographic studies on the ribosome, a large macromolecular assembly exhibiting severe nonisomorphism, extreme beam sensitivity and no internal symmetry.
abstract: Crystals, diffracting best to around 3 A, have been grown from intact large and small ribosomal subunits. The bright synchrotron radiation necessary for the collection of the higher-resolution X-ray diffraction data introduces significant decay even at cryo temperatures. Nevertheless, owing to the reasonable isomorphism of the recently improved crystals of the small ribosomal subunits, reliable phases have been extracted at medium resolution (5-6 A) and an interpretable five-derivative MIR map has been constructed. For the crystals of the large subunits, however, the situation is more complicated because at higher resolution (2.7-7 A) they suffer from substantial radiation sensitivity, a low level of isomorphism, instability of the longest unit-cell axis and nonisotropic mosaicity. The 8 A MIR map, constructed to gain insight into this unusual system, may provide feasible reasoning for the odd combination of the properties of these crystals as well as hints for future improvement. Parallel efforts, in which electron-microscopy-reconstructed images are being exploited for molecular-replacement studies, are also discussed.
authors.affiliation: Max-Planck-Research Unit for Ribosomal Structure, Hamburg, Germany. csyonath@weizmann.weizmann.ac.il
authors.forename: A
authors.initials: A
authors.lastname: Yonath
authors.forename: J
authors.initials: J
authors.lastname: Harms
authors.forename: H A
authors.initials: HA
authors.lastname: Hansen
authors.forename: A
authors.initials: A
authors.lastname: Bashan
authors.forename: F
authors.initials: F
authors.lastname: Schlünzen
authors.forename: I
authors.initials: I
authors.lastname: Levin
authors.forename: I
authors.initials: I
authors.lastname: Koelln
authors.forename: A
authors.initials: A
authors.lastname: Tocilj
authors.forename: I
authors.initials: I
authors.lastname: Agmon
authors.forename: M
authors.initials: M
authors.lastname: Peretz
authors.forename: H
authors.initials: H
authors.lastname: Bartels
authors.forename: W S
authors.initials: WS
authors.lastname: Bennett
authors.forename: S
authors.initials: S
authors.lastname: Krumbholz
authors.forename: D
authors.initials: D
authors.lastname: Janell
authors.forename: S
authors.initials: S
authors.lastname: Weinstein
authors.forename: T
authors.initials: T
authors.lastname: Auerbach
authors.forename: H
authors.initials: H
authors.lastname: Avila
authors.forename: M
authors.initials: M
authors.lastname: Piolleti
authors.forename: S
authors.initials: S
authors.lastname: Morlang
authors.forename: F
authors.initials: F
authors.lastname: Franceschi
mesh_terms: D000818:Animals; D018360:Crystallography, X-Ray; D006801:Humans; D012270:Ribosomes / Q000737:chemistry* / Q000648:ultrastructure*; D014961:X-Ray Diffraction