Starvation-induced expression of retron-Ec107 and the role of ppGpp in multicopy single-stranded DNA production.

Abstract

Multicopy single-stranded DNA is found as a small single-stranded RNA-DNA complex in certain wild-type strains of Escherichia coli as well as in other gram-negative bacteria. Using the promoter region of the previously characterized retron-Ec107 from E. coli ECOR70, I constructed a chromosomally located lacZ operon fusion. Examination of expression from the PEc107 promoter showed that activity increased sharply when cells entered stationary phase in rich medium or when they were starved for phosphate. The nucleotide guanosine-3',5'-bispyrophosphate was found to be a positive regulator of retron-Ec107 expression. Its presence is required for starvation-induced transcription of retron-Ec107 and multicopy single-stranded DNA production. It was also found that expression from the retron promoter is independent of the sigma factor sigmaS.

• Authors: P J Herzer
• Journal: Journal of bacteriology (J Bacteriol) Vol. 178 Issue 15 Pg. 4438-44 (Aug 1996) ISSN: 0021-9193 [Print] United States
• PMID: 8755870 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Single-Stranded
• RNA, Bacterial
• Sigma Factor
• msDNA
• Guanosine Tetraphosphate

Topics

• Base Sequence
• Cloning, Molecular
• DNA, Single-Stranded (biosynthesis, chemistry, genetics)
• Escherichia coli (genetics, growth & development, metabolism)
• Gene Expression
• Genes, Bacterial
• Guanosine Tetraphosphate (metabolism)
• Lac Operon
• Molecular Sequence Data
• Nucleic Acid Conformation
• Promoter Regions, Genetic
• RNA, Bacterial (biosynthesis, chemistry, genetics)
• Sigma Factor (metabolism)