Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 2015 Oct 27;112(43):13150-4. doi: 10.1073/pnas.1515348112. Epub 2015 Oct 5.

Variable genetic architectures produce virtually identical molecules in bacterial symbionts of fungus-growing ants.

Author information

1
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115;
2
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706.
3
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115; jon_clardy@hms.harvard.edu.

Abstract

Small molecules produced by Actinobacteria have played a prominent role in both drug discovery and organic chemistry. As part of a larger study of the actinobacterial symbionts of fungus-growing ants, we discovered a small family of three previously unreported piperazic acid-containing cyclic depsipeptides, gerumycins A-C. The gerumycins are slightly smaller versions of dentigerumycin, a cyclic depsipeptide that selectively inhibits a common fungal pathogen, Escovopsis. We had previously identified this molecule from a Pseudonocardia associated with Apterostigma dentigerum, and now we report the molecule from an associate of the more highly derived ant Trachymyrmex cornetzi. The three previously unidentified compounds, gerumycins A-C, have essentially identical structures and were produced by two different symbiotic Pseudonocardia spp. from ants in the genus Apterostigma found in both Panama and Costa Rica. To understand the similarities and differences in the biosynthetic pathways that produced these closely related molecules, the genomes of the three producing Pseudonocardia were sequenced and the biosynthetic gene clusters identified. This analysis revealed that dramatically different biosynthetic architectures, including genomic islands, a plasmid, and the use of spatially separated genetic loci, can lead to molecules with virtually identical core structures. A plausible evolutionary model that unifies these disparate architectures is presented.

KEYWORDS:

biosynthetic gene clusters; chemical ecology; horizontal gene transfer; natural products; symbiosis

PMID:
26438860
PMCID:
PMC4629343
DOI:
10.1073/pnas.1515348112
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center