Analysis of the 5' regulatory region of the gene for delta-aminolevulinic acid synthetase of Rhizobium meliloti.
AUTOR(ES)
Leong, S A
RESUMO
Transcriptional regulation of the delta-aminolevulinic acid synthetase gene of Rhizobium meliloti was investigated under conditions of normal vegetative growth and during symbiosis with the legume host alfalfa. S1 nuclease mapping and DNA sequence analysis indicated that transcription originates from two sites separated by 238 base pairs. A deletion analysis of the putative promoter regions P1 and P2, corresponding to the proximal and distal RNA start sites, was carried out with Bal-31 nuclease. Promoter function was monitored as beta-galactosidase activity after fusing the deletions to lac Z and introducing them into Rhizobium on a broad host range plasmid. The data obtained suggest that both regions function equivalently as promoters. The DNA sequences of P1 and P2 show considerable homology in the region between -35 and the start of transcription. Both contain a -35 region that is analogous to the consensus E. coli promoter sequence, while the -10 region is dissimilar. No resemblance was found between either P1 or P2 and the promoter regions of genes under general nitrogen control.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=321926Documentos Relacionados
- Control of hemoglobin synthesis in the cultured chick blastoderm by delta-aminolevulinic acid synthetase: increase in the rate of hemoglobin formation with delta-aminolevulinic acid.
- delta-Aminolevulinic acid synthase from Euglena gracilis.
- Delta-aminolevulinic acid-requiring mutant from Escherichia coli.
- Biosynthesis of delta-aminolevulinic acid by blue-green algae (cyanobacteria).
- Nucleotide sequence of rat liver delta-aminolevulinic acid dehydratase cDNA.