Spontaneous mutations in pcaH and -G, structural genes for protocatechuate 3,4-dioxygenase in Acinetobacter calcoaceticus.
AUTOR(ES)
Gerischer, U
RESUMO
Bacteria containing spontaneous null mutations in pcaH and -G, structural genes for protocatechuate 3,4-dioxygenase, were selected by exposure of an Acinetobacter calcoaceticus strain to physiological conditions in which expression of the genes prevents growth. The parental bacterial strain exhibits high competence for natural transformation, and this procedure was used to characterize 94 independently isolated spontaneous mutations. Four of the mutations were caused by integration of a newly identified insertion sequence, IS1236. Many (22 of 94) of the mutations were lengthy deletions, the largest of which appeared to eliminate at least 17 kb of DNA containing most of the pca-qui-pob supraoperonic gene cluster. DNA sequence determination revealed that the endpoints of four smaller deletions (74 to 440 bp in length) contained DNA sequence repetitions aligned imprecisely with the sites of mutation. Analysis of direct and inverted DNA sequence repetitions associated with the sites of mutation suggested the existence of DNA slippage structures that make unhybridized nucleotides particularly susceptible to mutation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=176741Documentos Relacionados
- Molecular Characterization of the Genes pcaG and pcaH, Encoding Protocatechuate 3,4-Dioxygenase, Which Are Essential for Vanillin Catabolism in Pseudomonas sp. Strain HR199
- Cloning of Protocatechuate 3,4-Dioxygenase Genes from Bradyrhizobium japonicum USDA110
- Cloning, sequencing, and expression of the Pseudomonas putida protocatechuate 3,4-dioxygenase genes.
- Cloning, expression, and regulation of the Pseudomonas cepacia protocatechuate 3,4-dioxygenase genes.
- Positive Selection for Mutations Affecting Bioconversion of Aromatic Compounds in Agrobacterium tumefaciens: Analysis of Spontaneous Mutations in the Protocatechuate 3,4-Dioxygenase Gene