User:Eric Martz/Introduction to Structural Bioinformatics I
From Proteopedia
How to find, visualize, and understand 3D protein molecular structures
by Eric Martz, October 2 and 4, 2012
for Prof. Steven Sandler's course Microbiology 565: Laboratory in Molecular Genetics
University of Massachusetts, Amherst MA USA
Protein Structure
- 1. Amino acid sequence + protein chain conformation = protein function.
- A. Conformation can be a stable fold or intrinsically unstructured. Both commonly exist in the same protein molecule.
- B. Conformation is specified by sequence.
- Folded domains fold spontaneously (Anfinson, 1960's[1]), or with the help of chaperonins.
- The denaturation (unfolding) of a folded domain destroys its function.
- 2. Structure Knowledge.
- A. Although sequence specifies fold, scientists cannot yet predict the fold from the sequece. Therefore, fold must be determined by empirical (experimental) methods. The most common methods for determining the 3D structure of a protein molecule are:
- X-ray crystallography, 88%.
- Nuclear magnetic resonance (NMR) in aqueous solution, 11%.
- NMR is limited to small proteins (30 kD or smaller).
- High resolution cryo-electron microscopy, 0.5%.
- A. Although sequence specifies fold, scientists cannot yet predict the fold from the sequece. Therefore, fold must be determined by empirical (experimental) methods. The most common methods for determining the 3D structure of a protein molecule are:
Notes and References
- ↑ For a brief overview of Anfinson's protein folding experiments in the 1960's, see the first paragraph at Intrinsically Disordered Protein.
