title: Assessment of Anabaena sp. Strain PCC 7120 as a Heterologous Expression Host for Cyanobacterial Natural Products: Production of Lyngbyatoxin A.
abstract: Cyanobacteria are well-known producers of natural products of highly varied structure and biological properties. However, the long doubling times, difficulty in establishing genetic methods for marine cyanobacteria, and low compound titers have hindered research into the biosynthesis of their secondary metabolites. While a few attempts to heterologously express cyanobacterial natural products have occurred, the results have been of varied success. Here, we report the first steps in developing the model freshwater cyanobacterium Anabaena sp. strain PCC 7120 (Anabaena 7120) as a general heterologous expression host for cyanobacterial secondary metabolites. We show that Anabaena 7120 can heterologously synthesize lyngbyatoxin A in yields comparable to those of the native producer, Moorea producens, and detail the design and use of replicative plasmids for compound production. We also demonstrate that Anabaena 7120 recognizes promoters from various biosynthetic gene clusters from both free-living and obligate symbiotic marine cyanobacteria. Through simple genetic manipulations, the titer of lyngbyatoxin A can be improved up to 13-fold. The development of Anabaena 7120 as a general heterologous expression host enables investigation of interesting cyanobacterial biosynthetic reactions and genetic engineering of their biosynthetic pathways.
authors.forename: Patrick
authors.initials: P
authors.lastname: Videau
authors.forename: Kaitlyn N
authors.initials: KN
authors.lastname: Wells
authors.forename: Arun J
authors.initials: AJ
authors.lastname: Singh
authors.affiliation: Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego , La Jolla, California 92093, United States.
authors.forename: William H
authors.initials: WH
authors.lastname: Gerwick
authors.forename: Benjamin
authors.initials: B
authors.lastname: Philmus
mesh_terms: D017033:Anabaena / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D001688:Biological Products / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000235:genetics; D000458:Cyanobacteria / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics; D008235:Lyngbya Toxins / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D001688:Biological Products; D008235:Lyngbya Toxins; C019457:lyngbyatoxin A
keywords: nonribosomal peptide synthetase; promoter fusion; secondary metabolites