Protein Structure and Function Prediction Using I-TASSER

Curr Protoc Bioinformatics. 2015 Dec 17;52:5.8.1-5.8.15. doi: 10.1002/0471250953.bi0508s52.


I-TASSER is a hierarchical protocol for automated protein structure prediction and structure-based function annotation. Starting from the amino acid sequence of target proteins, I-TASSER first generates full-length atomic structural models from multiple threading alignments and iterative structural assembly simulations followed by atomic-level structure refinement. The biological functions of the protein, including ligand-binding sites, enzyme commission number, and gene ontology terms, are then inferred from known protein function databases based on sequence and structure profile comparisons. I-TASSER is freely available as both an on-line server and a stand-alone package. This unit describes how to use the I-TASSER protocol to generate structure and function prediction and how to interpret the prediction results, as well as alternative approaches for further improving the I-TASSER modeling quality for distant-homologous and multi-domain protein targets.

Keywords: I-TASSER; protein function annotation; protein structure prediction; threading.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Amino Acid Sequence
  • Binding Sites
  • Computational Biology / methods*
  • Databases, Protein
  • Gene Ontology
  • Ligands
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Proteins / chemistry*
  • Sequence Alignment
  • Solvents


  • Ligands
  • Proteins
  • Solvents