Molecular replacement for small-molecule crystal structure determination from X-ray and electron diffraction data with reduced resolution.
Acta Crystallogr A Found Adv
; 79(Pt 6): 504-514, 2023 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-37855135
ABSTRACT
The resolution of 3D electron diffraction (ED) data of small-molecule crystals is often relatively poor, due to either electron-beam radiation damage during data collection or poor crystallinity of the material. Direct methods, used as standard for crystal structure determination, are not applicable when the data resolution falls below the commonly accepted limit of 1.2â
Å. Therefore an evaluation was carried out of the performance of molecular replacement (MR) procedures, regularly used for protein structure determination, for structure analysis of small-molecule crystal structures from 3D ED data. In the course of this study, two crystal structures of Bi-3812, a highly potent inhibitor of the oncogenic transcription factor BCL6, were determined the structure of α-Bi-3812 was determined from single-crystal X-ray data, the structure of ß-Bi-3812 from 3D ED data, using direct methods in both cases. These data were subsequently used for MR with different data types, varying the data resolution limit (1, 1.5 and 2â
Å) and by using search models consisting of connected or disconnected fragments of BI-3812. MR was successful with 3D ED data at 2â
Å resolution using a search model that represented 74% of the complete molecule.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Acta Crystallogr A Found Adv
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Alemanha