Lucia Rothman-Denes, Ph.D.

APPOINTMENTS

  • Professor, Department of Molecular Genetics and Cell Biology, Committee on Genetics, Committee on Microbiology

EDUCATION

Ph.D., University of Buenos Aires, 1967

Licenciado, University of Buenos Aires, 1964

CONTACT INFORMATION

The University of Chicago
CLSC 829A 
920 East 58th Street 
Chicago, Illinois 60637

lbrd@uchicago.edu

Phone:  (773) 702-1083

RESEARCH SUMMARY

Bacterial and Bacteriophage Physiology and Transcription

Regulation of RNA polymerase activity is the main target of control of gene expression in all organisms. Our laboratory studies structure-function relationships, mechanisms of promoter recognition and mechanisms of activation of three DNA-dependent RNA polymerases (RNAP) using genetic, biochemical and biophysical approaches. Bacteriophage N4-coded virion RNAP (vRNAP) is a 3,500 amino acid long polypeptide that transcribes single-stranded, promoter containing templates with specificity. We have shown that determinants of promoter recognition include specific sequences and a small hairpin on the template strand, which is formed on double-stranded DNA through specific sequences and supercoiling. Promoter utilization requires E. coli single-stranded DNA binding protein (SSB) at physiological superhelical densities. The vRNAP domains responsible for promoter recognition and catalysis and the mechanism of Eco SSB activation are under investigation. Bacteriophage N4-coded RNAPII is a heterodimer with sequence homology to the T7 RNAP; however, it does not transcribe promoter-containing dsDNA templates. An additional small, phage-coded, which required in vivo for N4 RNAPII transcription, is a SSB that specifically recruits N4 RNAPII to ssDNA. The interaction of proteins at the promoter and the mechanism of promoter recognition are under investigation. The N4-coded SSB activates bacteriophage N4 late transcription through direct interaction with the ß' subunit of E. coli RNAP, i.e. acting as an allosteric effector. The mechanism of activation and the role of this region of RNAP in E. coli transcription are being studied. Our studies have shown that, unexpectedly, single-stranded DNA binding proteins (SSB) act as transcription activators.

Research Papers on PubMed