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 Werner, J. Articles by Misra, R. Search for Related Content PubMed PubMed Citation Articles by Werner, J. Articles by Misra, R.

Assembly of TolC, a Structurally Unique and Multifunctional Outer Membrane Protein of Escherichia coli K-12

John Werner,¹ Anne Marie Augustus,^2, and Rajeev Misra^1,3*

Molecular and Cellular Biology Graduate Program,¹ Department of Chemistry and Biochemistry,² Department of Microbiology, Arizona State University, Tempe, Arizona 85287³

Received 13 May 2003/ Accepted 20 August 2003

TolC is a multifunctional outer membrane protein of Escherichia coli that folds into a novel -ß-barrel conformation absent in the other model outer membrane proteins used in assembly studies. The data presented in this work show that the unique folded structure of TolC reflects a unique assembly pathway. During its assembly, the newly translocated nascent TolC monomers are released in the periplasm. Maturation of these nascent monomers, and possibly their oligomerization, in the periplasm precedes their insertion in the outer membrane. The completion of the assembly process is signaled by the development of a characteristic proteinase K-resistant fragment generated by cleavage at a single, periplasmically exposed, protease-sensitive site of the membrane-anchored trimer. None of the assembly steps of TolC is affected by known folding factors, such as SurA, Skp, and lipopolysaccharide, which have profound effects on the assembly of other model trimeric outer membrane proteins. Two assembly-defective TolC mutants were isolated and characterized. One of the mutants (TolC_I106N) was defective in the folding of nascent monomers, while the other (TolC_S350F) was impaired in steps involving trimerization and membrane insertion of folded monomers.

Present address: Cell and Molecular Biology Program, Duke University, Durham, NC 27708.

This article has been cited by other articles:

• Vuong, P., Bennion, D., Mantei, J., Frost, D., Misra, R. (2008). Analysis of YfgL and YaeT Interactions through Bioinformatics, Mutagenesis, and Biochemistry. J. Bacteriol. 190: 1507-1517 [Abstract] [Full Text]  
• DeVito, J. A. (2008). Recombineering with tolC as a Selectable/Counter-selectable Marker: remodeling the rRNA Operons of Escherichia coli. Nucleic Acids Res 36: e4-e4 [Abstract] [Full Text]  
• Masi, M., Vuong, P., Humbard, M., Malone, K., Misra, R. (2007). Initial Steps of Colicin E1 Import across the Outer Membrane of Escherichia coli. J. Bacteriol. 189: 2667-2676 [Abstract] [Full Text]  
• Charlson, E. S., Werner, J. N., Misra, R. (2006). Differential Effects of yfgL Mutation on Escherichia coli Outer Membrane Proteins and Lipopolysaccharide.. J. Bacteriol. 188: 7186-7194 [Abstract] [Full Text]  
• Vediyappan, G., Borisova, T., Fralick, J. A. (2006). Isolation and Characterization of VceC Gain-of-Function Mutants That Can Function with the AcrAB Multiple-Drug-Resistant Efflux Pump of Escherichia coli. J. Bacteriol. 188: 3757-3762 [Abstract] [Full Text]  
• Mogensen, J. E., Kleinschmidt, J. H., Schmidt, M. A., Otzen, D. E. (2005). Misfolding of a bacterial autotransporter. Protein Sci. 14: 2814-2827 [Abstract] [Full Text]  
• Augustus, A. M., Celaya, T., Husain, F., Humbard, M., Misra, R. (2004). Antibiotic-Sensitive TolC Mutants and Their Suppressors. J. Bacteriol. 186: 1851-1860 [Abstract] [Full Text]