Lessons From the Studies of a CC Bond Forming Radical SAM Enzyme in Molybdenum Cofactor Biosynthesis.

Journal Article (Journal Article)

MoaA is one of the founding members of the radical S-adenosyl-L-methionine (SAM) superfamily, and together with the second enzyme, MoaC, catalyzes the construction of the pyranopterin backbone structure of the molybdenum cofactor (Moco). However, the exact functions of both MoaA and MoaC had remained ambiguous for more than 2 decades. Recently, their functions were finally elucidated through successful characterization of the MoaA product as 3',8-cyclo-7,8-dihydro-GTP (3',8-cH2GTP), which was shown to be converted to cyclic pyranopterin monophosphate (cPMP) by MoaC. 3',8-cH2GTP was produced in a small quantity and was highly oxygen sensitive, which explains why this compound had previously eluded characterization. This chapter describes the methodologies for the characterization of MoaA, MoaC, and 3',8-cH2GTP, which together significantly altered the view of the mechanism of the pyranopterin backbone construction during the Moco biosynthesis. Through this chapter, we hope to share not only the protocols to study the first step of Moco biosynthesis but also the lessons we learned from the characterization of the chemically labile biosynthetic intermediate, which would be informative for the study of many other metabolic pathways and enzymes.

Full Text

Duke Authors

Cited Authors

  • Pang, H; Yokoyama, K

Published Date

  • 2018

Published In

Volume / Issue

  • 606 /

Start / End Page

  • 485 - 522

PubMed ID

  • 30097104

Pubmed Central ID

  • PMC6263026

Electronic International Standard Serial Number (EISSN)

  • 1557-7988

Digital Object Identifier (DOI)

  • 10.1016/bs.mie.2018.04.014


  • eng

Conference Location

  • United States