This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hirano, T. Articles by Macnab, R. M. Search for Related Content PubMed PubMed Citation Articles by Hirano, T. Articles by Macnab, R. M.

 Previous Article  |  Next Article 

Journal of Bacteriology, April 2003, p. 2485-2492, Vol. 185, No. 8
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.8.2485-2492.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Substrate Specificity Classes and the Recognition Signal for Salmonella Type III Flagellar Export

Takanori Hirano,^1, Tohru Minamino,² Keiichi Namba,^2,3 and Robert M. Macnab^1*

Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114,¹ Protonic NanoMachine Project, ERATO, JST, Seika, Kyoto 619-0237,² Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan³

Received 24 October 2002/ Accepted 31 January 2003

Most flagellar proteins of Salmonella are exported to their assembly destination via a specialized apparatus. This apparatus is a member of the type III superfamily, which is widely used for secretion of virulence factors by pathogenic bacteria. Extensive studies have been carried out on the export of several of the flagellar proteins, most notably the hook protein (FlgE), the hook-capping protein (FlgD), and the filament protein flagellin (FliC). This has led to the concept of two export specificity classes, the rod/hook type and the filament type. However, little direct experimental evidence has been available on the export properties of the basal-body rod proteins (FlgB, FlgC, FlgF, and FlgG), the putative MS ring-rod junction protein (FliE), or the muramidase and putative rod-capping protein (FlgJ). In this study, we have measured the amounts of these proteins exported before and after hook completion. Their amounts in the culture supernatant from a flgE mutant (which is still at the hook-type specificity stage) were much higher than those from a flgK mutant (which has advanced to the filament-type specificity stage), placing them in the same class as the hook-type proteins. Overproduction of FliE, FlgB, FlgC, FlgF, FlgG, or FlgJ caused inhibition of the motility of wild-type cells and inhibition of the export of the hook-capping protein FlgD. We also examined the question of whether export and translation are linked and found that all substrates tested could be exported after protein synthesis had been blocked by spectinomycin or chloramphenicol. We conclude that the amino acid sequence of these proteins suffices to mediate their recognition and export.

Present address: Aizawa Team, Soft Nano-Machine Project, CREST, c/o Kochi Sangyo, Tochigi 329-1206, Japan.

This article has been cited by other articles:

• Chevance, F. F.V., Takahashi, N., Karlinsey, J. E., Gnerer, J., Hirano, T., Samudrala, R., Aizawa, S.-I., Hughes, K. T. (2007). The mechanism of outer membrane penetration by the eubacterial flagellum and implications for spirochete evolution. Genes Dev. 21: 2326-2335 [Abstract] [Full Text]  
• Lee, H. J., Hughes, K. T. (2006). Posttranscriptional Control of the Salmonella enterica Flagellar Hook Protein FlgE. J. Bacteriol. 188: 3308-3316 [Abstract] [Full Text]  
• Eggenhofer, E., Rachel, R., Haslbeck, M., Scharf, B. (2006). MotD of Sinorhizobium meliloti and Related {alpha}-Proteobacteria Is the Flagellar-Hook-Length Regulator and Therefore Reassigned as FliK. J. Bacteriol. 188: 2144-2153 [Abstract] [Full Text]  
• Frye, J., Karlinsey, J. E., Felise, H. R., Marzolf, B., Dowidar, N., McClelland, M., Hughes, K. T. (2006). Identification of New Flagellar Genes of Salmonella enterica Serovar Typhimurium. J. Bacteriol. 188: 2233-2243 [Abstract] [Full Text]  
• Wilharm, G., Lehmann, V., Krauss, K., Lehnert, B., Richter, S., Ruckdeschel, K., Heesemann, J., Trulzsch, K. (2004). Yersinia enterocolitica Type III Secretion Depends on the Proton Motive Force but Not on the Flagellar Motor Components MotA and MotB. Infect. Immun. 72: 4004-4009 [Abstract] [Full Text]  
• Kelly, A., Goldberg, M. D., Carroll, R. K., Danino, V., Hinton, J. C. D., Dorman, C. J. (2004). A global role for Fis in the transcriptional control of metabolism and type III secretion in Salmonella enterica serovar Typhimurium. Microbiology 150: 2037-2053 [Abstract] [Full Text]