Jakubowski, S.J. and Kerr, J.E. and Garza, I. and Krishnamoorthy, V. and Bayliss, R. and Waksman, Gabriel and Christie, P.J. (2009) Agrobacterium VirB10 domain requirements for type IV secretion and T pilus biogenesis. Molecular Microbiology 71 (3), pp. 779-794. ISSN 0950-382X.Full text not available from this repository.
Agrobacterium tumefaciens VirB10 couples inner membrane (IM) ATP energy consumption to substrate transfer through the VirB/D4 type IV secretion (T4S) channel and also mediates biogenesis of the virB-encoded T pilus. Here, we determined the functional importance of VirB10 domains denoted as the: (i) N-terminal cytoplasmic region, (ii) transmembrane (TM) α-helix, (iii) proline-rich region (PRR) and (iv) C-terminal β-barrel domain. Mutations conferring a transfer- and pilus-minus (Tra-, Pil-) phenotype included PRR deletion and β-barrel substitution mutations that prevented VirB10 interaction with the outer membrane (OM) VirB7–VirB9 channel complex. Mutations permissive for substrate transfer but blocking pilus production (Tra+, Pil-) included a cytoplasmic domain deletion and TM domain insertion mutations. Another class of Tra+ mutations also selectively disrupted pilus biogenesis but caused release of pilin monomers to the milieu; these mutations included deletions of α-helical projections extending from the β-barrel domain. Our findings, together with results of Cys accessibility studies, indicate that VirB10 stably integrates into the IM, extends via its PRR across the periplasm, and interacts via its β-barrel domain with the VirB7–VirB9 channel complex. The data further support a model that distinct domains of VirB10 regulate formation of the secretion channel or the T pilus.
|School or Research Centre:||Birkbeck Schools and Research Centres > School of Science > Biological Sciences|
|Date Deposited:||04 Aug 2010 14:09|
|Last Modified:||17 Apr 2013 12:17|
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