Suppression of mutant phenotypes of the Agrobacterium tumefaciens VirB11 ATPase by overproduction of VirB proteins.
AUTOR(ES)
Zhou, X R
RESUMO
The Agrobacterium tumefaciens VirB11 ATPase is postulated to assemble with VirB proteins and the VirD4 protein into a transport system which is dedicated to the export of oncogenic nucleoprotein particles to plant cells. To gain genetic evidence for interactions between VirB11 and other subunits of this transport system, we screened a PCR-mutagenized virB11 library for alleles that diminish the virulence of the wild-type strain A348. Two classes of alleles displaying negative dominance were identified. One class failed to complement a delta virB11 mutation, indicating that the corresponding mutant proteins are nonfunctional. The second class complemented the delta virB11 mutation, indicating that the mutant proteins are fully functional in strains devoid of native VirB11. Mutations of both classes of alleles were in codons for residues clustered in two regions of VirB11, both located outside the Walker A nucleotide binding motif. All dominant alleles were suppressed at least to some extent by multicopy expression of the virB9, virB10, and/or virB11 genes. Taken together, results of these investigations indicate that (i) a functional T-complex transporter is composed of more than one VirB11 subunit and (ii) VirB11 undergoes complex formation with VirB9 and VirB10 during transporter biogenesis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=179474Documentos Relacionados
- Self-Assembly of the Agrobacterium tumefaciens VirB11 Traffic ATPase
- Characterization of membrane and protein interaction determinants of the Agrobacterium tumefaciens VirB11 ATPase.
- Genetic complementation analysis of the Agrobacterium tumefaciens virB operon: virB2 through virB11 are essential virulence genes.
- Complementation analysis of Agrobacterium tumefaciens Ti plasmid virB genes by use of a vir promoter expression vector: virB9, virB10, and virB11 are essential virulence genes.
- Role of Agrobacterium VirB11 ATPase in T-Pilus Assembly and Substrate Selection