Previous Article | Next Article 
Journal of Bacteriology, January 2005, p. 488-497, Vol. 187, No. 2
0021-9193/05/$08.00+0 doi:10.1128/JB.187.2.488-497.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
Nature of the Promoter Activated by C.PvuII, an Unusual Regulatory Protein Conserved among Restriction-Modification Systems
Dieter Knowle,
Robert E. Lintner,
Yara M. Touma, and
Robert M. Blumenthal*
Department of Microbiology and Immunology and Program in Bioinformatics and Proteomics/Genomics, Medical College of Ohio, Toledo, Ohio
Received 8 June 2004/
Accepted 8 October 2004
A widely distributed family of small regulators, called C proteins, controls a subset of restriction-modification systems. The C proteins studied to date activate transcription of their own genes and that of downstream endonuclease genes; this arrangement appears to delay endonuclease expression relative to that of the protective methyltransferase when the genes enter a new cell. C proteins bind to conserved sequences called C boxes. In the PvuII system, the C boxes have been reported to extend from 23 to +3 relative to the transcription start for the gene for the C protein, an unexpected starting position relative to a bound activator. This study suggests that transcript initiation within the C boxes represents initial, C-independent transcription of pvuIICR. The major C protein-dependent transcript appears to be a leaderless mRNA starting farther downstream, at the initiation codon for the pvuIIC gene. This conclusion is based on nuclease S1 transcript mapping and the effects of a series of nested deletions in the promoter region. Furthermore, replacing the region upstream of the pvuIIC initiation codon with a library of random oligonucleotides, followed by selection for C-dependent transcription, yielded clones having sequences that resemble 10 promoter hexamers. The 35 hexamer of this promoter would lie within the C boxes. However, the spacing between C boxes/35 and the apparent 10 hexamer can be varied by ±4 bp with little effect. This suggests that, like some other activator-dependent promoters, PpvuIICR may not require a 35 hexamer. Features of this transcription activation system suggest explanations for its broad host range.
* Corresponding author. Mailing address: Department of Microbiology and Immunology, Medical College of Ohio, 3055 Arlington Ave., Toledo, OH 43614-5806. Phone: (419) 383-5422. Fax: (419) 383-3002. E-mail:
rblumenthal{at}mco.edu.
Supplemental material for this article may be found at http://jb.asm.org/.
Journal of Bacteriology, January 2005, p. 488-497, Vol. 187, No. 2
0021-9193/05/$08.00+0 doi:10.1128/JB.187.2.488-497.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Bogdanova, E., Zakharova, M., Streeter, S., Taylor, J., Heyduk, T., Kneale, G., Severinov, K.
(2009). Transcription regulation of restriction-modification system Esp1396I. Nucleic Acids Res
37: 3354-3366
[Abstract]
[Full Text]
-
Sorokin, V., Severinov, K., Gelfand, M. S.
(2009). Systematic prediction of control proteins and their DNA binding sites. Nucleic Acids Res
37: 441-451
[Abstract]
[Full Text]
-
Mruk, I., Blumenthal, R. M.
(2009). Tuning the relative affinities for activating and repressing operators of a temporally regulated restriction-modification system. Nucleic Acids Res
37: 983-998
[Abstract]
[Full Text]
-
McGeehan, J. E., Streeter, S. D., Thresh, S.-J., Ball, N., Ravelli, R. B. G., Kneale, G. G.
(2008). Structural analysis of the genetic switch that regulates the expression of restriction-modification genes. Nucleic Acids Res
36: 4778-4787
[Abstract]
[Full Text]
-
Mruk, I., Blumenthal, R. M.
(2008). Real-time kinetics of restriction-modification gene expression after entry into a new host cell. Nucleic Acids Res
36: 2581-2593
[Abstract]
[Full Text]
-
Bogdanova, E., Djordjevic, M., Papapanagiotou, I., Heyduk, T., Kneale, G., Severinov, K.
(2008). Transcription regulation of the type II restriction-modification system AhdI. Nucleic Acids Res
36: 1429-1442
[Abstract]
[Full Text]
-
Mruk, I., Rajesh, P., Blumenthal, R. M.
(2007). Regulatory circuit based on autogenous activation-repression: roles of C-boxes and spacer sequences in control of the PvuII restriction-modification system. Nucleic Acids Res
35: 6935-6952
[Abstract]
[Full Text]
-
Papapanagiotou, I., Streeter, S. D., Cary, P. D., Kneale, G. G.
(2007). DNA structural deformations in the interaction of the controller protein C.AhdI with its operator sequence. Nucleic Acids Res
0: gkm129v1-8
[Abstract]
[Full Text]
-
Semenova, E., Minakhin, L., Bogdanova, E., Nagornykh, M., Vasilov, A., Heyduk, T., Solonin, A., Zakharova, M., Severinov, K.
(2005). Transcription regulation of the EcoRV restriction-modification system. Nucleic Acids Res
33: 6942-6951
[Abstract]
[Full Text]