Characterization of NcsB2 as a promiscuous naphthoic acid/coenzyme A ligase integral to the biosynthesis of the enediyne antitumor antibiotic neocarzinostatin

BIOL 180

Heather A. Cooke, cookeha@bc.edu and Steve D. Bruner. Department of Chemistry, Boston College, 2609 Beacon St., Chestnut Hill, MA 02467
The enediyne antitumor antibiotic neocarzinostatin (NCS) is produced by Streptomyces carzinostaticus ATCC15944. The biosynthetic pathway for the naphthoic acid moiety on the NCS chromophore is proposed to involve five enzymes: NcsB, NcsB1, NcsB2, NcsB3 and NcsB4. Both in vivo and in vitro experiments were used to demonstrate that NcsB2 is required for the selection and activation of 7-methoxy-5-methyl-2-hydroxy-1-naphthoic acid for attachment to the NCS enediyne core. Activation has been shown to occur via a naphthoyl-AMP ester and subsequent formation of the corresponding coenzyme A ester. The finding that NcsB2 exhibits promiscuous substrate specificity towards a diverse set of naphthoic acid analogs with substitutions on the 2, 5, and/or 7 positions presents an outstanding opportunity to produce novel analogs of NCS by engineering its biosynthetic cluster.

 

Frontiers in Chemical Biology
5:00 PM-7:00 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Biological Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007