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Abstract Detail


MSA - Systematics/Evolution

Bushley, Kathryn E. [1], Turgeon, B. Gillian [1].

Modular Evolution of nonribosomal peptide synthetases.

Non-ribosomal peptide synthetases (NRPSs) are multimodular enzymes that make non-ribosomal peptides (NRPs) through a thiotemplate mechanism independent of ribosomes. NRPs have important roles in both development and niche-specific success of filamentous fungi in addition to the well-known, useful, biological effects on other organisms including antibiotic, immunosuppressant, antitumor, and virulence-promoting activities. The modular structure of NRPSs, consisting of repeated units of Adenylation (A), Thiolation (T), and Condensation (C) domains, allows for both rapid evolution of novel genes, as well as flexibility in biosynthetic strategies. The mechanisms by which these genes evolve are likely complex, involving tandem duplication, duplication and loss, recombination, gene conversion, and fusion/fission of modular units (either single domains or A-T-C modules). We have addressed this issue, using several phylogenetic approaches in two datasets: 1) among homologs of the relatively conserved NRPSs that biosynthesize intracellular siderophores found in all filamentous ascomycetes and some basidiomycetes and 2) among NRPSs found in sequenced genomes of closely related species. Our results suggest that 1) tandem duplication of complete A-T-C units represents the most plausible explanation for the generation of multimodular genes, 2) loss and/or swapping of A domains involved in substrate recognition may represent a mechanism for rapid evolution of new compounds, and 3) genes conserved across filamentous ascomycetes are also conserved in closely related species, while others appear more prone to rapid duplication and rearrangement.


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1 - Cornell University, Plant Pathology & Plant-Microbe Biology, 334 Plant Science Building, Ithaca, NY, 14853-5904, USA

Keywords:
Nonribosomal Peptide Synthetases
evolution.

Presentation Type: Poster:Posters for Topics
Session: P2
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM
Number: P2SE064
Abstract ID:859

Canceled

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