Cancelled Professor Audrey Lamb from the University of Texas at San Antonio will present a seminar. Evidence for the chemical mechanism of dihydroxybutanone phosphate (DHBP) synthase from riboflavin biosynthesis Abstract: RibB (3,4-dihydroxy-2-butanone 4-phosphate synthase) is a magnesium-dependent enzyme that excises the C4 of D-ribulose-5-phosphate (D-Ru5P) as formate. This chemistry forms the four-carbon substrate for RibE