Assignment of secondary structure from Cα coordinates

✍ Scribed by Kaiwan Gan; Peter Alexander; James M. Coxon; A. John McKinnon; Gillian H. Worth

• Publisher: Wiley (John Wiley & Sons)
• Year: 1997
• Tongue: English
• Weight: 134 KB
• Volume: 41
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/(sici)1097-0282(19970405)41:4<367::aid-bip2>3.0.co;2-k

✦ Synopsis

A multiple regression analysis has established a nonlinear relationship between the backbone dihedral angles and the C a coordinates obtained from the x-ray crystal structures of 14 proteins. The regression equations have been applied to predict specific dihedral angles of each residue in the backbone of 24 proteins. Overall this method (Nonlinear Regression Distance Torsion) predicts values of f and c within a {45Њ window of those found in the x-ray structure with an accuracy of 94 and 91% and within a {30Њ window of 88 and 81%. Two methods for the assignment of motif from C a coordinates are reported. For the first method, motif is assigned from the dihedral angles predicted using the regression equations. By the second method, motif of the ith residue is assigned from the distance C a i01 to C a i/2 (v 6 ) and torsional angle C a i01 , C a i , C a i/1 , C a i/2 (v 13 ). For the 24 proteins, 23.7% of the residues by the former method and 19.6% by the latter method are assigned differently than in the Protein Data Bank. ᭧ 1997 John Wiley & Sons, Inc.