Username


Password

Forgot Password?

Preview

Sign-in free and Explore the Exciting World of BiomedExperts:
  • Over 1,800,000 Profiles
  • More than 3,500 Organizations worldwide
  • State of the Art Network Visualizations
  • Manage your own Profile
  • Locate Experts in your Country/Region
  • Locate Experts in your 1. and 2. Level Network
  • Connect to Experts Worldwide

find experts for

Sign-in to see more
2007: Fridman Micha; Balibar Carl J; Lupoli Tania; Kahne Daniel; Walsh Christopher T; Garneau-Tsodikova Sylvie
Chemoenzymatic formation of novel aminocoumarin antibiotics by the enzymes CouN1 and CouN7.
Biochemistry 2007;46(28):8462-71.
The aminocoumarin antibiotics novobiocin, clorobiocin, and coumermycin A1 are highly potent inhibitors of the bacterial type II topoisomerase DNA gyrase. The key pharmacophore of both clorobiocin and coumermycin A1, the 5-methyl-2-pyrrolylcarbonyl moiety, targets the ATP-binding site of GyrB. The 5-methyl-2-pyrrolylcarbonyl group is transferred by the acyltransferases Clo/CouN7 from the carrier proteins Clo/CouN1 to the 3'-hydroxyl of the l-noviosyl scaffold during the late steps of clorobiocin and coumermycin A1 biosynthesis. We first examined the substrate specificity of the purified thiolation domain protein CouN1 in becoming primed by the phosphopantetheinyltransferase Sfp using a variety of synthetic CoA analogues of the 5-methyl-2-pyrrolylcarbonyl moiety. The acyl-S-CouN1 thioesters were then assayed as donors to the 3'-OH group of descarbamoylnovobiocin by the acyltransferase CouN7, resulting in 21 novel variants with heterocyclic acyl groups installed on the noviosyl moiety of the aminocoumarin scaffold. Scaleup of a 5-methylthiophene derivative yielded a compound with activity against both Gram-negative and Gram-positive bacteria. The minimal inhibitory concentration found for the Gram-positive bacteria was comparable to that of novobiocin.

Post to CiteULike

Sign in free and see...

Visualized networks:
See your personal network in
sophisticated graphical views
GeoTargeted Searches:
Locate experts around the world
and connect with global collaborators
Research Profiles:
See the visualized research activity
of experts around the globe
Sign-in to see more