|
|
||||||||
McMaster University, Department of Biology and Antimicrobial Research Centre, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada
Correspondence
Christian Baron
baronc{at}mcmaster.ca
The Agrobacterium tumefaciens VirB/D4 type IV secretion system (T4SS) mediates the transfer of single-stranded DNA and protein virulence factors into plant cells, and also determines the assembly of the T-pilus, which is believed to play a role in host recognition. The T-pilus is composed of the major component VirB2 and the minor component VirB5. Using immuno-electron microscopy we detected the major component VirB2 along the entire length of detached T-pili, but not on cell-bound T-pili or on the cell surface. In contrast, the minor T-pilus component VirB5 was detected on the tips of cell-bound T-pili as well as on the ends of detached T-pili and on the cell surface. To gain further insights into the role of VirB5 we introduced changes at its C terminus. C-terminal deletions of up to four amino acids and alanine replacements did not abolish T-pilus formation and incorporation of the VirB5 variants at the tip, although they did impact the length of T-pili. Also, these changes differentially affected the ability of the T4SS to transfer DNA into plant and bacterial recipients, suggesting differential effects on host-cell specificity. The data presented here suggest that VirB5 localizes at the T-pilus tip, and provide novel insights into its role during the type IV secretion process.
Supplementary data are available with the online version of this paper.
This article has been cited by other articles:
![]() |
J. G. Hoey, F. Valois-Cruz, H. Goldenberg, Y. Voskoboynik, J. Pfiffner, R. C. Tilton, E. Mordechai, and M. E. Adelson Development of an Immunoglobulin M Capture-Based Enzyme-Linked Immunosorbent Assay for Diagnosis of Acute Infections with Bartonella henselae Clin. Vaccine Immunol., February 1, 2009; 16(2): 282 - 284. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Aly, L. Krall, F. Lottspeich, and C. Baron The Type IV Secretion System Component VirB5 Binds to the trans-Zeatin Biosynthetic Enzyme Tzs and Enables Its Translocation to the Cell Surface of Agrobacterium tumefaciens J. Bacteriol., March 1, 2008; 190(5): 1595 - 1604. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |