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J Bacteriol. Jan 1994; 176(2): 518–519.
PMCID: PMC205077

An insertional point mutation inactivates NolR repressor in Rhizobium meliloti 1021.

Abstract

In the majority of Rhizobium meliloti isolates, nod gene expression is controlled by NolR, but this is not the case in a few strains including the widely used laboratory strain 1021. In 1021, the lack of NolR function was shown to be due to a single insertional mutation in the C-terminal coding sequence which abolished the DNA-binding ability, though the helix-turn-helix motif remained intact. This indicates that the C-terminal part of the protein is also essential for DNA binding. We conclude that in this species, control of nod gene expression involves NolR and strain 1021 represents an exception in which the NolR function was lost by a single event.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Grunstein M, Hogness DS. Colony hybridization: a method for the isolation of cloned DNAs that contain a specific gene. Proc Natl Acad Sci U S A. 1975 Oct;72(10):3961–3965. [PMC free article] [PubMed]
  • Harrison SC, Aggarwal AK. DNA recognition by proteins with the helix-turn-helix motif. Annu Rev Biochem. 1990;59:933–969. [PubMed]
  • Kondorosi E, Gyuris J, Schmidt J, John M, Duda E, Hoffmann B, Schell J, Kondorosi A. Positive and negative control of nod gene expression in Rhizobium meliloti is required for optimal nodulation. EMBO J. 1989 May;8(5):1331–1340. [PMC free article] [PubMed]
  • Kondorosi E, Pierre M, Cren M, Haumann U, Buiré M, Hoffmann B, Schell J, Kondorosi A. Identification of NolR, a negative transacting factor controlling the nod regulon in Rhizobium meliloti. J Mol Biol. 1991 Dec 20;222(4):885–896. [PubMed]
  • Meade HM, Long SR, Ruvkun GB, Brown SE, Ausubel FM. Physical and genetic characterization of symbiotic and auxotrophic mutants of Rhizobium meliloti induced by transposon Tn5 mutagenesis. J Bacteriol. 1982 Jan;149(1):114–122. [PMC free article] [PubMed]
  • Pabo CO, Sauer RT. Protein-DNA recognition. Annu Rev Biochem. 1984;53:293–321. [PubMed]
  • Sanger F, Nicklen S, Coulson AR. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. [PMC free article] [PubMed]
  • Spaink HP. Rhizobial lipo-oligosaccharides: answers and questions. Plant Mol Biol. 1992 Dec;20(5):977–986. [PubMed]
  • Vijn I, das Nevas L, van Kammen A, Franssen H, Bisseling T. Nod factors and nodulation in plants. Science. 1993 Jun 18;260(5115):1764–1765. [PubMed]

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