title: SIR2000, a program for the automatic ab initio crystal structure solution of proteins.
abstract: A new phasing procedure is described working both in direct and in reciprocal space. The procedure has been implemented into the program SIR2000, the heir to SIR99, and it is able routinely to solve ab initio crystal structures of proteins without any use of prior information and any user intervention. The moduli and the flow diagram of SIR2000 are also described and its efficiency tested on several protein diffraction data sets. Success has been attained for crystal structures with up to almost 2000 non-hydrogen atoms in the asymmetric unit and resolution higher than 1.2 A. The phasing process is analysed to provide a better insight into the role of the various steps of the procedure.
authors.affiliation: Dipartimento di Scienze della Terra, Piazza Università, 06100 Perugia, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Burla
authors.forename: M
authors.initials: M
authors.lastname: Camalli
authors.forename: B
authors.initials: B
authors.lastname: Carrozzini
authors.forename: G L
authors.initials: GL
authors.lastname: Cascarano
authors.forename: C
authors.initials: C
authors.lastname: Giacovazzo
authors.forename: G
authors.initials: G
authors.lastname: Polidori
authors.forename: R
authors.initials: R
authors.lastname: Spagna
mesh_terms: D003461:Crystallography / Q000379:methods; D004798:Enzymes / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012984:Software; D012996:Solutions
chemical_list: D004798:Enzymes; D011506:Proteins; D012996:Solutions