qp.protonate.fix.flip_coordinated_HIS¶

qp.protonate.fix.flip_coordinated_HIS(points, res)[source]¶

Flip a histidine imidazole ring to orient nitrogen toward a metal.

Protoss assigns histidine tautomers and conformations, but sometimes the coordinating nitrogen (NE2 or ND1) is oriented away from the metal. This function detects when a carbon (CE1 or CD2) is closer to the metal than its adjacent nitrogen and flips the ring around the CB–CG axis to restore proper coordination geometry.

Parameters:

points (list of Bio.PDB.Atom.Atom) – Metal atoms to check coordination against.
res (Bio.PDB.Residue.Residue) – A histidine residue (modified in place).

Notes

The residue is modified in place. Hydrogen positions are adjusted to match the new ring orientation.