title: Characterization and engineering of the biosynthesis gene cluster for antitumor macrolides PM100117 and PM100118 from a marine actinobacteria: generation of a novel improved derivative.
abstract: BACKGROUND
  PM100117 and PM100118 are glycosylated polyketides with remarkable antitumor activity, which derive from the marine symbiotic actinobacteria Streptomyces caniferus GUA-06-05-006A. Structurally, PM100117 and PM100118 are composed of a macrocyclic lactone, three deoxysugar units and a naphthoquinone (NQ) chromophore that shows a clear structural similarity to menaquinone.
  
  
  RESULTS
  Whole-genome sequencing of S. caniferus GUA-06-05-006A has enabled the identification of PM100117 and PM100118 biosynthesis gene cluster, which has been characterized on the basis of bioinformatics and genetic engineering data. The product of four genes shows high identity to proteins involved in the biosynthesis of menaquinone via futalosine. Deletion of one of these genes led to a decay in PM100117 and PM100118 production, and to the accumulation of several derivatives lacking NQ. Likewise, five additional genes have been genetically characterized to be involved in the biosynthesis of this moiety. Moreover, the generation of a mutant in a gene coding for a putative cytochrome P450 has led to the production of PM100117 and PM100118 structural analogues showing an enhanced in vitro cytotoxic activity relative to the parental products.
  
  
  CONCLUSIONS
  Although a number of compounds structurally related to PM100117 and PM100118 has been discovered, this is, to our knowledge, the first insight reported into their biosynthesis. The structural resemblance of the NQ moiety to menaquinone, and the presence in the cluster of four putative menaquinone biosynthetic genes, suggests a connection between the biosynthesis pathways of both compounds. The availability of the PM100117 and PM100118 biosynthetic gene cluster will surely pave a way to the combinatorial engineering of more derivatives.
authors.affiliation: Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006, Oviedo, Asturias, Spain. raul.garcia.salcedo@gmx.com.
authors.forename: Raúl García
authors.initials: RG
authors.lastname: Salcedo
authors.affiliation: Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006, Oviedo, Asturias, Spain. olanocarlos@uniovi.es.
authors.forename: Carlos
authors.initials: C
authors.lastname: Olano
authors.affiliation: Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006, Oviedo, Asturias, Spain. criski57@gmail.com.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gómez
authors.affiliation: Drug Discovery Area, PharmaMar SA, Avda. de los Reyes 1, Colmenar Viejo, 28770, Madrid, Spain. rfernandez@pharmamar.com.
authors.forename: Rogelio
authors.initials: R
authors.lastname: Fernández
authors.affiliation: Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006, Oviedo, Asturias, Spain. afb@uniovi.es.
authors.forename: Alfredo F
authors.initials: AF
authors.lastname: Braña
authors.affiliation: Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006, Oviedo, Asturias, Spain. cmendezf@uniovi.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Méndez
authors.affiliation: Drug Discovery Area, PharmaMar SA, Avda. de los Reyes 1, Colmenar Viejo, 28770, Madrid, Spain. fdelacalle@pharmamar.com.
authors.forename: Fernando
authors.initials: F
authors.lastname: de la Calle
authors.affiliation: Departamento de Biología Funcional e Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006, Oviedo, Asturias, Spain. jasalas@uniovi.es.
authors.forename: José A
authors.initials: JA
authors.lastname: Salas
mesh_terms: D039903:Actinobacteria / Q000187:drug effects / Q000235:genetics*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics*; D002241:Carbohydrates / Q000096:biosynthesis / Q000737:chemistry; D019295:Computational Biology; D003198:Computer Simulation; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D005818:Genetic Engineering / Q000379:methods*; D016680:Genome, Bacterial; D018942:Macrolides / Q000737:chemistry / Q000494:pharmacology*; D005810:Multigene Family / Q000235:genetics*; D009285:Naphthoquinones / Q000737:chemistry / Q000378:metabolism; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D000970:Antineoplastic Agents; D002241:Carbohydrates; D018942:Macrolides; D009285:Naphthoquinones; D003577:Cytochrome P-450 Enzyme System