View source for Brian Chapados (whatido)

A short explanation of what I do for smart people who aren't biologists:

Enzymes are molecular machines that significantly speed up (typically > 1000-fold) chemical reactions.
Most enzymes are proteins[1], linear polymers of different subunits folded into
a three-dimensional structure. A subset of these enzymes operate directly on DNA,
either repairing damage or making a copy of DNA in preparation for cell division.
I determine the 3D-structures of enzymes at atomic resolution (1-3 angstroms or 1^-10 nanometers)
by growing crystals from purified enzyme samples, and measuring the intensities
of X-rays diffracted by the crystals. This process eventually yields
an "electron density map", which can be used to determine the position of atoms in the
crystal. Since I can see where that atoms are located, I can make predictions about how
pieces of the enzyme interact with DNA or other enzymes based on knowledge of 
chemistry. To test structure-based predictions about the function of enzymes, I change
the DNA encoding the enzyme to alter the chemical attributes of the enzyme at a known
location.  I can then test activity of the mutant enzyme in isolation, or in some cases,
introduce the modified enzyme into cells or organisms. Through iterative rounds of analysis,
I can determine how an enzyme works.

[1] Not all 'enzymes' are proteins. RNA and DNA can also fold into three-dimensional
structures, and catalyze chemical reactions.