Alessandro Pintar1, Oliviero Carugo, Sándor Pongor. 1. Protein Structure and Bioinformatics Group, International Center for Genetic Engineering and Biotechnology (ICGEB), AREA Science Park, Padriciano 99, 34012 Trieste, Italy. pintar@icgeb.trieste.it
Abstract
MOTIVATION: A simple and fast algorithm is described that calculates a measure of protrusion (cx) for atoms in protein structures, directly useable with the common molecular graphics programs. RESULTS: A sphere of predetermined radius is centered around each non-hydrogen atom, and the volume occupied by the protein and the free volume within the sphere (internal and external volumes, respectively) are calculated. Atoms in protruding regions have a high ratio (cx) between the external and the internal volume. The program reads a PDB file, and writes the output in the same format, with cx values in the B factor field. Output structure files can be directly displayed with standard molecular graphics programs like RASMOL, MOLMOL, Swiss-PDB Viewer and colored according to cx values. We show the potential use of this program in the analysis of two protein-protein complexes and in the prediction of limited proteolysis sites in native proteins. AVAILABILITY: The algorithm is implemented in a standalone program written in C and its source is freely available at ftp.icgeb.trieste.it/pub/CX or on request from the authors.
MOTIVATION: A simple and fast algorithm is described that calculates a measure of protrusion (cx) for atoms in protein structures, directly useable with the common molecular graphics programs. RESULTS: A sphere of predetermined radius is centered around each non-hydrogen atom, and the volume occupied by the protein and the free volume within the sphere (internal and external volumes, respectively) are calculated. Atoms in protruding regions have a high ratio (cx) between the external and the internal volume. The program reads a PDB file, and writes the output in the same format, with cx values in the B factor field. Output structure files can be directly displayed with standard molecular graphics programs like RASMOL, MOLMOL, Swiss-PDB Viewer and colored according to cx values. We show the potential use of this program in the analysis of two protein-protein complexes and in the prediction of limited proteolysis sites in native proteins. AVAILABILITY: The algorithm is implemented in a standalone program written in C and its source is freely available at ftp.icgeb.trieste.it/pub/CX or on request from the authors.
Authors: Marat D Kazanov; Yoshinobu Igarashi; Alexey M Eroshkin; Piotr Cieplak; Boris Ratnikov; Ying Zhang; Zhanwen Li; Adam Godzik; Andrei L Osterman; Jeffrey W Smith Journal: J Proteome Res Date: 2011-07-08 Impact factor: 4.466
Authors: Fadi Towfic; Cornelia Caragea; David C Gemperline; Drena Dobbs; Vasant Honavar Journal: Int J Data Min Bioinform Date: 2010 Impact factor: 0.667