PPS '97 - Section 10 - Tertiary Structure Part II

Section 10- Tertiary Structure Part II

In Section 9, we examined the interactions between elements of secondary structure, and then reviewed supersecondary structure.

We now progress to domains and their folds. A single protein may consist of several or many domains, but many proteins are single-domain.

Proteins with many (often repeated) domains are termed mosaic proteins.

Multi-domain proteins can have domains of very different types. Three major classes are globular (water-soluble), membrane-bound ('lipid soluble') and fibrous. On this basis, whole proteins can also be classified into different types.

You may wish to revisit the Overview of Protein Structure Terminology in the last Section.
Domains in Proteins by R. Sowdhamini, ICRF Unit of Structural Molecular Biology, Department of Crystallography, Birkbeck College; including notes on Roles of protein domains, by Stephen Rufino, ICRF Unit, Department of Crystallography, Birkbeck College
Domain Folds
You are also advised to study these databases of structural classification
- CATH - Class, Architecture, Topology, & Homology at University College London (Christine Orengo, Alex Michie, Janet Thornton, William Taylor)
- SCOP - Structural Classification of Proteins
  (Alexey G. Murzin, Steven E. Brenner, Tim J.P. Hubbard, and Cyrus Chothia)
- Structural Alignment Database (John Overington)
- Birkbeck's Protein Domain Database (R. Sowdhamini, S.D. Rufino, T.L. Blundell)
Mosaic Proteins
Types of Proteins
- Globular Proteins
- Membrane Proteins
- Fibrous and Structural Proteins - fibrous proteins such as tropomyosin, collagen and actin necessarily consist of an association of different polypeptide chains, so will be examined in the next section on Quaternary Structure, as will the proteins which constitute Virus Coats
also study the Rough Guide to Protein Types by Alan Mills

To best appreciate the material in this chapter, you should have your WWW browser configured to invoke RasMol as the helper application for chemical MIME type files.

This material includes some RasMol scripts, which may be copied directly into the RasMol command line from your browser window; alternatively download the script files and use the RasMol script command to execute them.

Help is available on Using RasMol Scripts in the Course Material

Thanks to

Alan Mills, Venus Internet Ltd
R. Sowdhamini, ICRF Unit of Structural Molecular Biology, Department of Crystallography, Birkbeck College
Stephen Rufino, ICRF Unit of Structural Molecular Biology, Department of Crystallography, Birkbeck College
Janet M. Thornton, Biomolecular Structure and Modelling,Department of Biochemistry and Molecular Biology, University College London

Index to Course Material

Last updated 7th April '97