5.1.2 Sphere Refinement

Sphere refinement selects residues within a certain distance of the residue at the centre of the screen and includes them for real space refinement. In this way, one can select residues that are not in a linear range. This technique is useful for refining disulfide bonds and glycosidic linkages.

To enable sphere refinement, Right-mouse in the vertical toolbutton menu, Manage buttons -> [Tick] Sphere Refine -> Apply. You will need a python-enabled Coot to do this.

The following adds a key binding (Shift-R) that refines resides that are within 3.5Å of the residue at the centre of the screen:

        
(define *sphere-refine-radius* 3.5)

(add-key-binding "Refine residues in a sphere" "R"
    (lambda ()
     (using-active-atom
      
      (let* ((rc-spec (list aa-chain-id aa-res-no aa-ins-code))
	     (ls (residues-near-residue aa-imol rc-spec *sphere-refine-radius*)))
	(refine-residues aa-imol (cons rc-spec ls))))))