Crystallographic and Other Physical Studies of Flavoenzymes

Oregon State University, Corvallis OR

Investigators

Abstract

The goal of this research is to carry out crystallographic studies on the flavoenzymes old yellow enzyme (OYE), lactate monooxygenase (LMO), ferredoxin:NADP + reductase (FNR) and glutathione reductase (GR). For OYE, the binding mode of NADPH and the structures of key mutants will be determined; for LMO, the wild type structure will be solved by MAD phasing and followed up by analysis of many existing mutants and catalytically informative complexes; for FNR, studies of the NADPH binding mode and specificity will be completed; and finally ultrahigh resolution crystal structures will be derived for the S. carlbergensis OYE, human GR, and corn root ferredoxin reductase. The investigations will give insight into the structure-function relations for each of these enzyme systems in particular, and increase our understanding of the biochemical regulation of flavin chemistry in general. The ultrahigh resolution analyses will provide a quantum leap in the level of structural detail available and usher in a new era in our structural understanding of flavins and flavoenzymes. The vitamin riboflavin is important because it becomes built into metabolic enzymes that carry out reactions crucial for life. In each riboflavin containing enzyme (flavoenzyme), the vitamin has a slightly different function that is defined by its protein environment. X-ray crystallography will be used to investigate the three-dimensional structures and chemical mechanisms of four different flavoenzymes that represent three of the most prevalent families of flavoenzymes found in nature.