We are attempting REFMAC refinement of a protein structure which is complexed with lactose. One of the rings (the one oriented away from the protein) loses the chair conformation which is flagged as a problem by COOT check chiral volumes. Is there anything we can do to restrain the ring as a chair and would this necessarily be a valid move? ie why can't the conformation deviate from the norm?
Rex Palmer Birkbeck College
