The building of protein structures from alpha-carbon coordinates.

A procedure for the construction of complete protein structures from only alpha-carbon coordinates is described. This involves building the backbone by sequential addition of Pro, Gly, or Ala residues. This main chain structure is then refined using molecular dynamics. Side chains are constructed by sequential addition of atoms with intermediate molecular dynamics refinement. For alpha lytic protease (a structure that is mostly beta sheet) a backbone root mean square deviation (RMSD) of 0.19 A and an overall RMSD of 1.24 A from the crystallographic coordinates are attained. For troponin C (67% alpha-helix), where the coordinates are available only for the alpha-carbons, a backbone RMSD of 0.41 A and an overall RMSD of 1.68 A are attained (fits kindly provided by Dr. Michael James and Natalie Strynadka). For flavodoxin a backbone RMSD of 0.49 A and an overall RMSD of 1.64 A were attained.