Phylogenetic and structural diversity of aromatically dense pili from environmental metagenomes

Bray, M. S.; Wu, J.; Padilla, C. C.; Stewart, F. J.; Fowle, D. A.; Henny, C.; Simister, R. L.; Thompson, K. J.; Crowe, S. A.; Glass, J. B.

doi:10.1101/668343

bioRxiv · 10.1101/668343

Phylogenetic and structural diversity of aromatically dense pili from environmental metagenomes

Bray, M. S.·Wu, J.·Padilla, C. C.·Stewart, F. J.·Fowle, D. A.·Henny, C.·Simister, R. L.·Thompson, K. J.·Crowe, S. A.·Glass, J. B.

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Abstract

Electroactive type IV pili, or e-pili, are used by some microbial species for extracellular electron transfer. Recent studies suggest that e-pili may be more phylogenetically and structurally diverse than previously assumed. Here, we used updated aromatic density thresholds ([≥]9.8% aromatic amino acids, [≤]22-aa aromatic gaps, and aromatic amino acids at residues 1, 24, 27, 50 and/or 51, and 32 and/or 57) to search for putative e-pilin genes in metagenomes from diverse ecosystems with active microbial metal cycling. Environmental putative e-pilins were diverse in length and phylogeny, and included truncated e-pilins in Geobacter spp., as well as longer putative e-pilins in Fe(II)-oxidizing Betaproteobacteria and Zetaproteobacteria.\n\nOriginality and SignificanceElectroactive pili (e-pili) are used by microorganisms to respire solid metals in their environment through extracellular electron transfer. Thus, e-pili enable microbes to occupy specific environmental niches. Additionally, e-pili have important potential for biotechnological applications. Currently the repertoire of known e-pili is small, and their environmental distribution is largely unknown. Using sequence analysis, we identified numerous genes encoding putative e-pili from diverse anoxic, metal-rich ecosystems. Our results expand the diversity of putative e-pili in environments where metal oxides may be important electron acceptors for microbial respiration.

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Bray, M. S., Wu, J., Padilla, C. C., Stewart, F. J., Fowle, D. A., Henny, C., Simister, R. L., Thompson, K. J., Crowe, S. A., Glass, J. B.. 2019-06-13. Phylogenetic and structural diversity of aromatically dense pili from environmental metagenomes. https://doi.org/10.1101/668343

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