How far are we from automatic crystal structure solution via molecular‐replacement techniques?. Issue 1 (2nd January 2020)

• Record Type: Journal Article
• Authors: Burla, Maria Cristina; Carrozzini, Benedetta; Cascarano, Giovanni Luca; Giacovazzo, Carmelo; Polidori, Giampiero
• Is Part Of: Acta crystallographica. Volume 76:Issue 1(2020)
• Page Start: 9
• Page End: 18
• Publication Date: 2020-01-02
• Subjects: molecular replacement -- proteins -- nucleic acids -- automated model building -- structure refinement; X-ray crystallography -- Periodicals; Crystallography -- Periodicals; Molecular biology -- Periodicals; Molecular structure -- Periodicals; Biomolecules -- Structure -- Periodicals; Cytology -- Periodicals; Biomolecules -- Structure; Crystallography; Cytology; Molecular biology; Molecular structure; X-ray crystallography; Periodicals; 548
• DOI: 10.1107/S2059798319015468
• Languages: English
• ISSNs: 2059-7983

Abstract

Abstract : An automatic pipeline based on molecular‐replacement phases is described for the automatic crystal structure solution of protein and DNA/RNA molecules. Abstract : Although the success of molecular‐replacement techniques requires the solution of a six‐dimensional problem, this is often subdivided into two three‐dimensional problems. REMO 09 is one of the programs which have adopted this approach. It has been revisited in the light of a new probabilistic approach which is able to directly derive conditional distribution functions without passing through a previous calculation of the joint probability distributions. The conditional distributions take into account various types of prior information: in the rotation step the prior information may concern a non‐oriented model molecule alone or together with one or more located model molecules. The formulae thus obtained are used to derive figures of merit for recognizing the correct orientation in the rotation step and the correct location in the translation step. The phases obtained by this new version of REMO 09 are used as a starting point for a pipeline which in its first step extends and refines the molecular‐replacement phases, and in its second step creates the final electron‐density map which is automatically interpreted by CAB, an automatic model‐building program for proteins and DNA/RNA structures.