Automation of refinement: low-resolution and beyond - Oleg Kovalevskiy
Success of macromolecular structure refinement (especially in difficult cases) may greatly depend on the optimisation of refinement parameters. These include not only parameters of the refinement program like REFMAC5. For instance, at low resolution, since the ratio of the number of observations to adjustable parameters is small, it is necessary to use optimal complementary information (e.g., additional external restraints obtained from analysis of the homologous structures) for the refinement of such model. Manual optimisation of the refinement parameters and selection of homologues could be quite laborious and require certain level of expertise.
As a general trend, programs for macromolecular crystallography are moving towards full automation, including the handling of difficult cases. Human experts in their work follow some standard steps that could be viewed as a sort of algorithm. Such an algorithm can potentially be implemented as a computer program that may be used to treat even difficult cases with minimal user intervention. In this talk I will discuss challenges of the refinement at low resolution and automation tools available in CCP4 Suite for refinement at low, medium, and high resolution.