J. Bacteriol., 10 1996, 5668-5675, Vol 178, No. 19
Copyright © 1996, American Society for Microbiology

Bacteriophage PSP3 and phiR73 activator proteins: analysis of promoter specificities

B Julien and R Calendar
Department of Molecular and Cell Biology, University of California, Berkeley 94720-3204, USA.

Transcription from the late promoters of bacteriophage P2 and its satellite phage P4 is activated by a unique class of small, zinc- binding proteins. Using plasmid expression systems, we compared activators from two P2-like (helper) phages with those encoded by two satellite phages. The helper phage activators have more activity on the P4 phage sid promoter. In contrast, the satellite phage activators function better on the four late P2 promoters and on the P4 late leftward promoter. We purified one activator encoded by a P2-like phage and an activator from a satellite phage and determined their binding sites within the P2 and P4 late promoters. Differences in activity levels correlate with binding specificities; promoters that function best with the satellite phage activators have only one activator binding site centered at -55, while the P4 sid promoter, which has more activity with helper phage activators, has a second binding site centered at -18. Surprisingly, DNase I footprinting revealed only very minor differences in promoter binding by the two activators reported here and the P4 activator reported previously. Thus, the differences in transcriptional activity are probably due to interactions between the activators and RNA polymerase, rather than interactions between the activators and DNA.

This article has been cited by other articles:

• Contursi, P., Cannio, R., Prato, S., She, Q., Rossi, M., Bartolucci, S. (2007). Transcriptional Analysis of the Genetic Element pSSVx: Differential and Temporal Regulation of Gene Expression Reveals Correlation between Transcription and Replication. J. Bacteriol. 189: 6339-6350 [Abstract] [Full Text]  
• Markov, D., Christie, G. E., Sauer, B., Calendar, R., Park, T., Young, R., Severinov, K. (2004). P2 Growth Restriction on an rpoC Mutant Is Suppressed by Alleles of the Rz1 Homolog lysC. J. Bacteriol. 186: 4628-4637 [Abstract] [Full Text]  
• Christie, G. E., Anders, D. L., McAlister, V., Goodwin, T. S., Julien, B., Calendar, R. (2003). Identification of Upstream Sequences Essential for Activation of a Bacteriophage P2 Late Promoter. J. Bacteriol. 185: 4609-4614 [Abstract] [Full Text]  
• McAlister, V., Zou, C., Winslow, R. H., Christie, G. E. (2003). Purification and In Vitro Characterization of the Serratia marcescens NucC Protein, a Zinc-Binding Transcription Factor Homologous to P2 Ogr. J. Bacteriol. 185: 1808-1816 [Abstract] [Full Text]  
• Marciel, A. M., Highlander, S. K. (2001). Use of Operon Fusions in Mannheimia haemolytica To Identify Environmental and cis-Acting Regulators of Leukotoxin Transcription. Infect. Immun. 69: 6231-6239 [Abstract] [Full Text]  
• Winslow, R. H., Julien, B., Calendar, R., Christie, G. E. (1998). An Upstream Sequence Element Required for NucC-Dependent Expression of the Serratia marcescens Extracellular Nuclease. J. Bacteriol. 180: 6064-6067 [Abstract] [Full Text]  
• Reiter, K., Lam, H., Young, E., Julien, B., Calendar, R. (1998). A Complex Control System for Transcriptional Activation from the sid Promoter of Bacteriophage P4. J. Bacteriol. 180: 5151-5158 [Abstract] [Full Text]