Mutants of Agrobacterium tumefaciens with elevated vir gene expression

Journal Article · Thu Aug 15 00:00:00 EDT 1991 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.88.16.6941· OSTI ID:5226625

Pazour, G J; Ta, C N; Das, A ^[1]

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1. University of Minnesota, St. Paul (USA)

Expression of Agrobacterium tumefaciens virulence (vir) genes requires virA, virG, and a plant-derived inducing compound such as acetosyringone. To identify the critical functional domains of virA and virG, a mutational approach was used. Agrobacterium A136 harboring plasmid pGP159, which contains virA, virG, and a reporter virB:lacZ gene fusion, was mutagenized with UV light or nitrosoguanidine. Survivors that formed blue colonies on a plate containing 5-bromo-4-chloro-3-indolyl beta-D-galactoside were isolated and analyzed. Quantification of beta-galactosidase activity in liquid assays identified nine mutant strains. By plasmid reconstruction and other procedures, all mutations mapped to the virA locus. These mutations caused an 11- to 560-fold increase in the vegetative level of virB:lacZ reporter gene expression. DNA sequence analysis showed that the mutations are located in four regions of VirA: transmembrane domain one, the active site, a glycine-rich region with homology to ATP-binding sites, and a region at the C terminus that has homology to the N terminus of VirG.

• OSTI ID: 5226625
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 88:16; ISSN 0027-8424
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
54 ENVIRONMENTAL SCIENCES
BACTERIA
GENE REGULATION
GENE MUTATIONS
RADIOINDUCTION
NITROSO COMPOUNDS
MUTAGENESIS
AMINO ACID SEQUENCE
ATP
DNA SEQUENCING
ENZYME ACTIVITY
GALACTOSIDASE
GENOTYPE
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PLASMIDS
ULTRAVIOLET RADIATION
VIRULENCE
CELL CONSTITUENTS
ELECTROMAGNETIC RADIATION
ENZYMES
GLYCOSYL HYDROLASES
HYDROLASES
MICROORGANISMS
MOLECULAR STRUCTURE
MUTATIONS
NUCLEOTIDES
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATIONS
STRUCTURAL CHEMICAL ANALYSIS
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