How mithramycin stereochemistry dictates its structure and DNA binding function. Issue 5 (4th April 2019)

• Record Type: Journal Article
• Authors: Hou, Caixia; Rohr, Jürgen; Parkin, Sean; Tsodikov, Oleg V.
• Is Part Of: MedChemComm. Volume 10:Issue 5(2019)
• Page Start: 735
• Page End: 741
• Publication Date: 2019-04-04
• Subjects: Pharmaceutical chemistry -- Periodicals; 615.19
• DOI: 10.1039/c9md00100j
• Languages: English
• ISSNs: 2040-2503

Abstract

Abstract : The crystal structures of mithramycin and its analogue reveal how the chemistry of mithramycin shapes it for DNA binding. Abstract : An aureolic acid natural product mithramycin (MTM) has been known for its potent antineoplastic properties. MTM inhibits cell growth by binding in the minor groove of double-stranded DNA as a dimer, in which the two molecules of MTM are coordinated to each other through a divalent metal ion. A crystal structure of an MTM analogue, MTM SA-Phe, in the active metal ion-coordinated dimeric form demonstrates how the stereochemical features of MTM define the helicity of the dimeric scaffold for its binding to a right-handed DNA double helix. We also show crystallographically and biochemically that MTM, but not MTM SA-Phe, can be inactivated by boric acid through formation of a large macrocyclic species, in which two molecules of MTM are crosslinked to each other through 3-side chain–boron–sugar intermolecular bonds. We discuss these structural and biochemical properties in the context of MTM biosynthesis and the design of MTM analogues as anticancer therapeutics.