Why structure biology?
Structure biology is a research field that tries to answer biological questions by determining 3D structures of biological molecules including proteins and nucleic acids. Structure information of these molecules are very powerful so that they can answer many biological questions.
Biological molecules especially proteins have unique 3D structures that determine their functions. The reason why drugs work is because of this. Drugs tightly bind to unique shapes of cleaves of proteins created by their complex 3D structures and stop signal cascades. For instance, if you have headache, you take pain killers, which bind to proteins that mediate signal cascades causing headache. Drugs compete off cellular molecules that are supported to mediate pain signals by binding to target proteins. If the molecules cannot bind the proteins, signals stop so you don't feel pain. Drugs and cellular molecules have complementary shapes to cleaves of target proteins. Shapes of cleaves are different among proteins; therefore, we can specifically target certain proteins by drugs. Therefore, having knowledge of 3D structures of proteins is great advantage for drug design because we need to design chemicals complementray to the shapes of cleaves of target proteins. Without knowing the structures, we just need to screen a huge number of chemicals.
In addition to drug design, 3D structure of biological molecules provide extremely useful information for research. For instance, you can introduce mutations to abolish protein-protein interactions without disrupting 3D structures of proteins in order to study nature of the interactions. "Without disrupting 3D structures" is key. Proteins tend to have more than one functions. If you completely distroy target proteins by disrupting their 3D structures, you observe complex phenotypes that are caused by loss of different functions. However, people sometime want to study a specific function of a protein. Then, they can use 3D structures to know how to abolish the function by mutating a particular residue. Related to this topic, many inherited mutations causing diseases result from one mutation in one gene. With 3D structures, people can possibly explain why such mutation causes disease.
