This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by von Lintig, J Articles by Schröder, J Search for Related Content PubMed PubMed Citation Articles by von Lintig, J Articles by Schröder, J

 Previous Article  |  Next Article 

J Bacteriol. 1994 January; 176(2): 495-503

research-article

Opine-regulated promoters and LysR-type regulators in the nopaline (noc) and octopine (occ) catabolic regions of Ti plasmids of Agrobacterium tumefaciens.

Institut für Biologie II, Universität Freiburg, Germany.

ABSTRACT

Essential steps in the uptake and catabolism of the plant tumor metabolites nopaline and octopine in Agrobacterium spp. are performed by proteins encoded in the nopaline catabolic (noc) and octopine catabolic (occ) regions of Ti plasmids. We investigated the opine activation of the genes by using (i) promoter studies of Agrobacterium spp. and (ii) analysis of the promoter interaction with the regulatory proteins NocR (noc) and OccR (occ). The noc region contained two nopaline-induced promoters (Pi1[noc] and Pi2[noc]) and one autogenously regulated promoter (Pr [control of NocR expression]). Pi2 and Pr overlapped and were divergently oriented (Pi2 [noc]). DNA binding studies and DNase I footprints indicated that NocR bound specifically to single binding sites in Pi1[noc] and Pi2/Pr[noc] and that Pi2 and Pr were regulated from the same binding site. The binding was independent of the inducer nopaline, and nopaline caused small changes in the footprint. The promoters in the noc and occ regions shared sequence motif and contained the sequence T-N11-A, which is characteristic for LysR-type-regulated promoters. The occ region contained one octopine-induced and one autogenously regulated promoter (Pi/Pr[occ]) in the same arrangement as Pi2/Pr[noc] in the noc region. Promoter deletions indicated that sequences flanking the OccR binding site determined the extent of induction, although they did not bind OccR. The promoter bound OccR in the absence and presence of octopine. The opine caused a change in the mobility of the DNA-protein complex with the complete promoter. The resected fragments did not reveal this opine-induced shift, and it was also not detectable with the DNA-NocR complexes with the two promoters of the noc region.

This article has been cited by other articles:

• Kim, H. S., Yi, H., Myung, J., Piper, K. R., Farrand, S. K. (2008). Opine-Based Agrobacterium Competitiveness: Dual Expression Control of the Agrocinopine Catabolism (acc) Operon by Agrocinopines and Phosphate Levels. J. Bacteriol. 190: 3700-3711 [Abstract] [Full Text]  
• Oger, P., Farrand, S. K. (2002). Two Opines Control Conjugal Transfer of an Agrobacterium Plasmid by Regulating Expression of Separate Copies of the Quorum-Sensing Activator Gene traR. J. Bacteriol. 184: 1121-1131 [Abstract] [Full Text]  
• Zhu, J., Oger, P. M., Schrammeijer, B., Hooykaas, P. J. J., Farrand, S. K., Winans, S. C. (2000). The Bases of Crown Gall Tumorigenesis. J. Bacteriol. 182: 3885-3895 [Full Text]  
• Kok, R. G., D'Argenio, D. A., Ornston, L. N. (1998). Mutation Analysis of PobR and PcaU, Closely Related Transcriptional Activators in Acinetobacter. J. Bacteriol. 180: 5058-5069 [Abstract] [Full Text]  
• Chlumsky, L. J., Zhang, L., Jorns, M. S. (1995). Sequence Analysis of Sarcosine Oxidase and Nearby Genes Reveals Homologies with Key Enzymes of Folate One-carbon Metabolism. J. Biol. Chem. 270: 18252-18259 [Abstract] [Full Text]