Dr. Ogasawara visited Duke to give a seminar about his studies on peptide natural product biosynthesis. We had a group meeting with him and had a very insightful discussion. It was great to have you here, and we look forward to more interactions in the future! Dr. Ogasawara is an assistant professor at Hokkaido University and the 2018 recipient of the award for young researchers from Japan Society for Bioscience, Biotechnology, and Agrochemistry.
This paper describes the mechanistic characterization of a yeast beta-1,3-D-glucan synthase (GS). GS is a proven target of FDA-approved antifungal drugs, but its catalytic mechanism is poorly understood. Using a newly developed size exclusion chromatography (SEC) assay, we were able to monitor the chain elongation for the first time and found that GS catalyzes the formation of a long glucan (~2,000 – 7,000 mer) at an amazing efficiency (~50-60 Glc unit polymerized per sec). The use of substrate analogs also revealed that the enzyme catalyzes the polymerization at the nonreducing end. The study also discusses the first comprehensive model of the GS catalytic cycle.
Hai and Matthew won the poster award in the Biochemistry Department retreat. Hai presented his work on mitomycin biosynthesis, where he successfully demonstrated that the early steps of mitomycin biosynthesis proceed with intermediates linked to an acyl carrier protein (ACP). The work was published earlier this year. Matthew presented his progress in the study of nikkomycin/polyoxin biosynthesis. He received this award two years in a row! Congratulations to both of you.
Abhi gave a poster presentation of his work on the mechanism of (1,3)-beta-D-glucan synthase in the 2019 Enzymes Coenzymes and Pathway GRC, and won a poster award. Congratulations!!
Hai’s work on the characterization of MitE and MitB enzymes in mitomycin biosynthesis was published in ACS Biochemistry. In this paper, we provide experimental evidence that the early steps of mitomycin biosynthesis proceeds with the biosynthetic intermediates linked to an acyl carrier protein (ACP). This is one of the first examples of ACP-dependent non-PKS/NRPS pathways, and the first step towards understanding the complex mechanism of mitomycin biosynthesis.
Kenichi Yokoyama, Ph.D. has been selected as the 2019 recipient of the Pfizer Award in Enzyme Chemistry administered by the American Chemical Society (ACS). The Pfizer Award was established in 1945 and aims to stimulate fundamental research in enzyme chemistry by scientists, not over forty years of age. Dr. Yokoyama is the second recipient of this award in this department. The first awardee was Dr. Paul Modrich in 1983.
Matthew received the poster award in the Biochemistry annual retreat. He presented his thesis work on the biosynthesis studies of antifungal peptidyl nucleoside natural products. Congratulations!! This is the fifth poster award for the lab since the establishment in 2011.
In this paper, we described detailed protocols of expression, purification, and characterization of MoaA and MoaC, as well as the isolation and characterization of 3′,8-cH2GTP. The in situ 13C NMR assay method was also described so that anyone interested can determine the product of MoaA without going through extensive purification in anaerobic glove box. We hope these protocols are informative to whoever interested in Moco biosynthesis or any other related systems.
This review summarizes the functions and mechanisms of the emerging group of radical SAM enzymes that catalyze C-C bond formations during natural products and cofactor biosynthesis. The review focuses on the roles of these enzymes in the biosynthetic pathways, and the key mechanistic questions relevant to many of these enzymes. Numbers of C-C bond forming radical SAM enzymes are increasing, but their mechanistic characterizations are still in its infancy.
A biochemistry perspective summarizing our studies on the Moco and antifungal peptidyl nucleoside biosyntheses came out as ASAP. This perspective summarizes the works mainly achieved by Brad Hover, Ph.D., and Edward Lilla (Ph.D. to be soon…!). These discoveries were made through characterization of unique C-C bond forming radical SAM enzymes. Congratulations to the two talented students!!