>In collagen a hydroxyl group is bonded to the CD atom of the prolyl ring to >give an R configuration. >[IUPAC: (2S,4R)-4-hydroxypyrrolidine-2-carboxylic acid]
>The monomer dictionary file HYP.cif incorrectly specifies the S >configuration about the CD atom. I've written CD where I should say CG in the above. Peter ________________________________ From: CCP4 bulletin board on behalf of Peter Brick Sent: Fri 04/04/2008 18:24 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Error in configuration of hydroxyproline in HYP.cif Dear All, My colleague Erhard Hohenester has noticed that there is an error in the cif definition file for hydroxyproline distributed with CCP4 version 6.02 and used by Refmac, Coot (and Phenix). In collagen a hydroxyl group is bonded to the CD atom of the prolyl ring to give an R configuration. [IUPAC: (2S,4R)-4-hydroxypyrrolidine-2-carboxylic acid] The monomer dictionary file HYP.cif incorrectly specifies the S configuration about the CD atom. In HYP.cif the chirality is specified by the sign of the chiral volume formed by a scalar triple product: HYP chir_01 CA N CB C negativ HYP chir_02 CG CB OD CD positiv The second line should be: HYP chir_02 CG CB OD CD negativ Alternatively, one could change the atom order. Peter -- Peter Brick, Division of Cell and Molecular Biology, Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BW, UK Tel: 020-7594-7704 Fax: 020-7589-0191
