Editor: Stephen Smith
Production of pilus-like filaments in Geobacter sulfurreducens in the absence of the type IV pilin protein PilA
Article first published online: 23 JUN 2010
© 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 310, Issue 1, pages 62–68, September 2010
How to Cite
Klimes, A., Franks, A. E., Glaven, R. H., Tran, H., Barrett, C. L., Qiu, Y., Zengler, K. and Lovley, D. R. (2010), Production of pilus-like filaments in Geobacter sulfurreducens in the absence of the type IV pilin protein PilA. FEMS Microbiology Letters, 310: 62–68. doi: 10.1111/j.1574-6968.2010.02046.x
Present addresses: Richard H. Glaven, Naval Research Laboratories, Center for Biomolecular Science and Engineering, Washington, DC, USA. Hoa Tran, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Issue published online: 4 AUG 2010
- Article first published online: 23 JUN 2010
- Received 6 April 2010; revised 7 June 2010; accepted 9 June 2010.Final version published online 9 July 2010.
The pili of Geobacter sulfurreducens are of interest because of the apparent importance of the type IV pili in extracellular electron transfer. A strain of G. sulfurreducens, designated strain MA, produced many more pili than the previously studied DL-1 strain even though genome resequencing indicated that the MA and DL-1 genome sequences were identical. Filaments that looked similar to type IV pili in transmission electron micrographs were abundant even after the gene encoding PilA, the structural pilin protein, was deleted. The results of proteinase K treatment indicated that the filaments were proteinaceous. The simultaneous deletion of several genes encoding homologues of type II pseudopilins was required before the filaments were significantly depleted. The pilA-deficient MA strain attached to glass as well as the wild-type MA did, but strains in which three or four pseudopilin genes were deleted in addition to pilA had impaired attachment capabilities. These results demonstrate that there are several proteins that can yield pilin-like filaments in G. sulfurreducens and that some means other than microscopic observation is required before the composition of filaments can be unambiguously specified.