Relaxation of the resolution requirements for direct-methods phasing

Area of Science:

• Crystallography
• Structural Biology
• Materials Science

Background:

• Shake-and-bake phasing methods enable ab initio crystal structure solution for complex molecules.
• Current methods require high-resolution diffraction data (at least 1.2 Å) for successful structure determination.

Purpose of the Study:

• To improve shake-and-bake phasing methods for broader applicability.
• To enable crystal structure solution using lower resolution diffraction data.

Main Methods:

• Introduction of a new target function, R(2)(φ(h)), into the shake-and-bake procedure.
• Implementation of a real difference map strategy to enhance phasing capabilities.

Main Results:

• The modified shake-and-bake procedure successfully lowers the resolution requirement to approximately 1.5 Å.
• This advancement allows for the solution of crystal structures twice the size of those previously manageable.

Conclusions:

• The enhanced shake-and-bake method expands the scope of crystal structure analysis.
• This breakthrough facilitates the study of larger and more complex molecular structures with accessible diffraction data.