Structural biology

Structural biology is a branch of molecular biology, biochemistry, and biophysics concerned with the molecular structure of biological macromolecules, especially proteins and nucleic acids, how they acquire the structures they have, and how alterations in their structures affect their function. This subject is of great interest to biologists because macromolecules carry out most of the functions of cells, and it is only by coiling into specific three-dimensional shapes that they are able to perform these functions. This architecture, the "tertiary structure" of molecules, depends in a complicated way on each molecule's basic composition, or "primary structure."

History

The history of structural biology can be traced back to the work of Emil Fischer, who in the late 19th century suggested that enzymes (a type of protein) act as lock and key to the molecules they bind to and modify, an idea that implies a specific, rigid structure for each enzyme. The "lock and key" model is still used today to describe enzyme behavior, although it is now known to be an oversimplification.

Techniques

Structural biology employs a range of techniques to determine these structures, the most powerful of which are X-ray crystallography, NMR spectroscopy, and cryo-electron microscopy. These techniques allow scientists to visualize the exact arrangement of atoms within a molecule, and to see how a molecule changes shape as it undergoes a chemical reaction.

Applications

Structural biology has been used to understand the mechanisms of replication, transcription, translation, and cell function. It has also been used to understand the structures of pathogenic molecules and to develop new drugs and therapies. The field has contributed to the understanding of diseases such as Alzheimer's disease, Parkinson's disease, and HIV/AIDS.

See also

• Protein structure
• Nucleic acid structure
• Macromolecule
• Biochemistry
• Molecular biology
• Biophysics