Citrate Synthase Mutants of Agrobacterium Are Attenuated in Virulence and Display Reduced vir Gene Induction
| Autor: | Derek W. Wood, Maneewan Suksomtip, Pu Liu, Eugene W. Nester, Sumalee Tungpradabkul, Tamara Anderson |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Transcriptional Activation
Agrobacterium Mutant Virulence Citrate (si)-Synthase Biology medicine.disease_cause Microbiology Gene Expression Regulation Enzymologic Conserved sequence Plant Microbiology Plasmid Escherichia coli medicine Amino Acid Sequence Molecular Biology Gene Conserved Sequence DNA Primers Base Sequence Sequence Homology Amino Acid Gene Expression Regulation Bacterial Agrobacterium tumefaciens biology.organism_classification Molecular biology Peptide Fragments Sequence Alignment Genome Bacterial |
| Zdroj: | Journal of Bacteriology. 187:4844-4852 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.187.14.4844-4852.2005 |
| Popis: | A citrate synthase (CS) deletion mutant of Agrobacterium tumefaciens C58 is highly attenuated in virulence. The identity of the mutant was initially determined from its amino acid sequence, which is 68% identical to Escherichia coli and 77% identical to Brucella melitensis . The mutant lost all CS enzymatic activity, and a cloned CS gene complemented a CS mutation in Sinorhizobium . The CS mutation resulted in a 10-fold reduction in vir gene expression, which likely accounts for the attenuated virulence. When a plasmid containing a constitutive virG [ virG (Con)] locus was introduced into this mutant, the level of vir gene induction was restored to nearly wild-type level. Further, the virG (Con)-complemented CS mutant strain induced tumors that were similar in size and number to those induced by the parental strain. The CS mutation resulted in only a minor reduction in growth rate in a glucose-salts medium. Both the CS mutant and the virG (Con)-complemented CS strain displayed similar growth deficiencies in a glucose-salts medium, indicating that the reduced growth rate of the CS mutant could not be responsible for the attenuated virulence. A search of the genome of A. tumefaciens C58 revealed four proteins, encoded on different replicons, with conserved CS motifs. However, only the locus that when mutated resulted in an attenuated phenotype has CS activity. Mutations in the other three loci did not result in attenuated virulence and any loss of CS activity, and none were able to complement the CS mutation in Sinorhizobium . The function of these loci remains unknown. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|