APPROACHES TO VERY-LOW RESOLUTION PHASING OF THE RIBOSOME 50S PARTICLE FROM THERMUS-THERMOPHILUS BY THE FEW-ATOMS-MODELS AND MOLECULAR-REPLACEMENT METHODS

Citation
Ag. Urzhumtsev et al., APPROACHES TO VERY-LOW RESOLUTION PHASING OF THE RIBOSOME 50S PARTICLE FROM THERMUS-THERMOPHILUS BY THE FEW-ATOMS-MODELS AND MOLECULAR-REPLACEMENT METHODS, Acta crystallographica. Section D, Biological crystallography, 52, 1996, pp. 1092-1097
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Crystallography,"Biochemical Research Methods",Biology
ISSN journal
0907-4449
Volume
52
Year of publication
1996
Part
6
Pages
1092 - 1097
Database
ISI
SICI code
0907-4449(1996)52:<1092:ATVRPO>2.0.ZU;2-C
Abstract
Estimates for the phases of the X-ray diffraction data from the 50S ri bosomal particle of Thermus thermophilus has been made to an effective resolution around 80 Angstrom using the few-atoms-modes ab initio tec hnique [Lunin, Lunina, Petrova, Vernoslova, Urzhumtsev & Podjarny (199 5). Acta Cn st. D51, 896-903]. This technique models the density with a small number of Gaussian spheres to generate a large number of possi ble phase sets and then uses clustering algorithms to identify the bes t ones. independently, an envelope obtained from electron-micrograph i mage reconstruction [Yonath, Leonard & Wittmann (1987). Science, 236, 813-816] was oriented and positioned using the molecular-replacement t echnique, specially adapted to the very low resolution case [Urzhumtse v & Podjarny (1995). Acta Cryst. D51, 888-895]. The two methods show s imilar packing arrangements. The electron density calculated by the fe w-atoms-models technique without any assumption on the number of molec ules in asymmetric unit or on their shape shows recognizable features of the particle.