Cradle-loop barrels and the concept of metafolds in protein classification by natural descent

Curr Opin Struct Biol. 2008 Jun;18(3):358-65. doi: 10.1016/ Epub 2008 May 3.


Current classification systems for protein structure show many inconsistencies both within and between systems. The metafold concept was introduced to identify fold similarities by consensus and thus provide a more unified view of fold space. Using cradle-loop barrels as an example, we propose to use the metafold as the next hierarchical level above the fold, encompassing a group of topologically related folds for which a homologous relationship has been substantiated. We see this as an important step on the way to a classification of proteins by natural descent.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Models, Molecular
  • Protein Conformation
  • Protein Folding
  • Proteins / chemistry
  • Proteins / classification*


  • Proteins