Crystal structure of alpha ketoglutarate nonheme iron halogenase CytC3

BIOL 119

Cintyu Wong, cywong@mit.edu1, Danica P. Galonic, danica_galonic@hms.harvard.edu2, Christopher T. Walsh2, and Catherine L Drennan, cdrennan@mit.edu1. (1) Department of Chemistry, Massachusetts Institute of Technology, 77 Mass Ave, Cambridge, MA 02139, (2) Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Ave, Boston, MA 02115
Halogenated natural products, such as antibiotics and metabolites, are important for the organisms' survival. Different classes of halogenase enzymes involved in the biosynthesis of these halogenated natural products have been discovered. One class of the halogenase enzymes belong to the a-ketoglutarate (aKG) non-heme Fe(II) dependent dioxygenase family. These enzymes utilize the decarboxylation of aKG to catalyze oxidative reactions, usually hydroxylation, through hydrogen abstraction of unactivated carbons. CytC3, which belongs to this family, is an aKG-Fe(II) dependent halogenase that catalyses the chlorination of L-aminobutyric acid (ABA) to 1-amino-1-carboxycyclopropane (ACC) in cytothrienin A biosynthesis. The crystal structure of CytC3 with aKG and iron is described here to ~2.2 Å resolution. Structural comparison of CytC3 with other halogenase SyrB2 will be presented.
 

Poster Session
8:00 PM-10:00 PM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Biological Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007