title: Expression and isolation of antimicrobial small molecules from soil DNA libraries.
abstract: Natural products have been a critically important source of clinically relevant small molecule therapeutics. However, the discovery rate of novel structural classes of antimicrobial molecules has declined. Recently, increasing evidence has shown that the number of species cultivated from soil represents less than 1% of the total population, opening up the exciting possibility that these uncultured species may provide a large untapped pool from which novel natural products can be discovered. We have constructed and expressed in E. coli a BAC (bacterial artificial chromosome) library containing genomic fragments of DNA (5-120kb) isolated directly from soil organisms (S-DNA). Screening of the library resulted in the identification of several antimicrobial activities expressed by different recombinant clones. One clone (mg1.1) has been partially characterized and found to express several small molecules related to and including indirubin. These results show that genes involved in natural product synthesis can be cloned directly from S-DNA and expressed in a heterologous host, supporting the idea that this technology has the potential to provide novel natural products from the wealth of environmental microbial diversity and is a potentially important new tool for drug discovery.
authors.affiliation: Aventis Pharmaceuticals, Cambridge, MA 02139, USA. ian.macneil@aventis.com
authors.forename: I A
authors.initials: IA
authors.lastname: MacNeil
authors.forename: C L
authors.initials: CL
authors.lastname: Tiong
authors.forename: C
authors.initials: C
authors.lastname: Minor
authors.forename: P R
authors.initials: PR
authors.lastname: August
authors.forename: T H
authors.initials: TH
authors.lastname: Grossman
authors.forename: K A
authors.initials: KA
authors.lastname: Loiacono
authors.forename: B A
authors.initials: BA
authors.lastname: Lynch
authors.forename: T
authors.initials: T
authors.lastname: Phillips
authors.forename: S
authors.initials: S
authors.lastname: Narula
authors.forename: R
authors.initials: R
authors.lastname: Sundaramoorthi
authors.forename: A
authors.initials: A
authors.lastname: Tyler
authors.forename: T
authors.initials: T
authors.lastname: Aldredge
authors.forename: H
authors.initials: H
authors.lastname: Long
authors.forename: M
authors.initials: M
authors.lastname: Gilman
authors.forename: D
authors.initials: D
authors.lastname: Holt
authors.forename: M S
authors.initials: MS
authors.lastname: Osburne
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D022202:Chromosomes, Artificial, Bacterial; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000235:genetics; D004798:Enzymes / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D015723:Gene Library; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016366:Open Reading Frames; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004798:Enzymes; D012336:RNA, Ribosomal, 16S