Quarterly Reviews of Biophysics

Research Article

Structure and distribution of modules in extracellular proteins

Peer Borka1, A. Kristina Downinga2, Bruno Kieffera3 and Iain D. Campbella2

a1 Max-Delbrück-Center for Molecular Medicine, 13125 Berlin-Buch, Germany and European Molecular Biology Laboratory, 69117 Heidelberg, Germany

a2 Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK

a3 Groupe de Cancerogenese, IBMC de CNRS, 75084 Strasbourg, France

It has become standard practice to compare new amino-acid and nucleotide sequences with existing ones in the rapidly growing sequence databases. This has led to the recurring identification of certain sequence patterns, usually corresponding to less than 300 amino-acids in length. Many of these identifiable sequence regions have been shown to fold up to form a ‘domain’ structure; they are often called protein ‘modules’ (see definitions below). Proteins that contain such modules are widely distributed in biology, but they are particularly common in extracellular proteins.