Abstract
Old Yellow Enzyme (OYE) was isolated from brewer's bottom yeast in 1932 as the first flavoprotein, but its physiological and biochemical function has not been revealed to date. Recently, OYE homologous protein was identified as 12-oxophytodienoate 10,11-reductase (OPR) which catalyzes a reductive step in jasmonate biosynthetic pathway of plants. Moreover, it appears that OYE homologous proteins distribute in eubacteria and protozoa and some of them have catalytic activity to reduce the α-β unsaturated compounds. We have isolated 41-kDa flavoprotein from the flagella fraction of the brown algae, Scytosiphon lomentaria, in biochemical search of the photoreceptor protein for phototaxis. Amino acids sequence deduced from cloned cDNA revealed that 41-kDa flavoprotein from S. lomentaria, belongs to OYE family. We will discuss structure and physiological function of the flavoprotein by comparison with the homologous proteins.
