John D. Lipscomb, Principal Investigator

Structure and Mechanism of Oxygenase Enzymes

Oxygenase enzymes utilize molecular oxygen to oxidize a wide range of biological and man-made compounds with the incorporation of one or both atoms of oxygen from molecular oxygen in the products.

In the first project undertaken by this group, a series of dioxygenase enzymes was studied. These enzymes attack aromatic substrates with two hydroxyl substituents. The products are ring-open compounds containing both atoms of oxygen from O2. Their products are easily degraded by bacteria, thus allowing the enormous amounts of carbon stored in aromatic compounds in the environment to reenter the carbon cycle. Also, the dioxygenases allow manmade aromatics, some of which are carcinogens, to be degraded. In collaboration with Douglas Ohlendorf’s group, the researchers solved the crystal structures of three of these enzymes. Supercomputing Institute resources were used to examine the crystal structures and plan ongoing, site-directed mutagenesis studies.

The second class of oxygenase studied was typified by methane monoxygenase. This enzyme catalyzes the oxidation of methane to methanol with the incorporation of one atom of oxygen. Methane is generated in large quantities in the environment and is a potent greenhouse gas. It is prevented from reaching the atmosphere by the action of methane monoxygenase. Again in collaboration with Douglas Ohlendorf, the group solved the crystal structure of the critical hydroxylase component. Supercomputing Institute resources were used to visualize the structure and plan mutagenesis studies.

Research Group

Brian Brazeau, Graduate Student Researcher
Stephanie Groce, Graduate Student Researcher
Codrina Popescu, Research Associate
Michael Valley, Graduate Student Researcher
Matt Wolfe, Graduate Student Researcher