Please use this identifier to cite or link to this item:
Title: Agrobacterium VirB10 domain requirements for type IV secretion and T pilus biogenesis.
Authors: Jakubowski, SJ
Kerr, JE
Garza, I
Krishnamoorthy, V
Bayliss, R
Waksman, G
Christie, PJ
First Published: Feb-2009
Citation: MOL MICROBIOL, 2009, 71 (3), pp. 779-794
Abstract: 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) alpha-helix, (iii) proline-rich region (PRR) and (iv) C-terminal beta-barrel domain. Mutations conferring a transfer- and pilus-minus (Tra(-), Pil(-)) phenotype included PRR deletion and beta-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 alpha-helical projections extending from the beta-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 beta-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.
DOI Link: 10.1111/j.1365-2958.2008.06565.x
eISSN: 1365-2958
Type: Journal Article
Appears in Collections:Published Articles, Dept. of Biochemistry

Files in This Item:
There are no files associated with this item.

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.