Error estimates in atom coordinates and B factors in macromolecular crystallography

Area of Science:

• Crystallography
• Structural Biology
• Biophysics

Background:

• The diffraction precision index (DPI) was introduced by Cruickshank in 1999 to assess the precision of biological macromolecule crystal structures.
• Assessing atomic coordinate precision is crucial for understanding molecular dynamics and interactions.

Purpose of the Study:

• To review the evolution and application of the DPI for individual atom coordinates.
• To discuss advancements in estimating the precision of atomic displacement parameters (B factors).

Main Methods:

• Elaboration of the DPI to individual atom coordinates.
• Development of a webserver for transforming PDB entries with DPI-derived errors.
• Application of parallelized workflows for diffraction image data processing.

Main Results:

• The DPI method has been successfully applied to estimate errors in atom coordinates and assess atom movements.
• A webserver facilitates the integration of DPI-derived errors into PDB files.
• New methods provide estimates for the precision of B factors, addressing a long-standing challenge.

Conclusions:

• The DPI and its extensions provide valuable tools for evaluating the precision of crystallographic data.
• Accurate estimation of B factor precision is essential to avoid misinterpretations of structural dynamics.
• Advancements in computational methods enhance the reliability of structural analyses in structural biology.