February 8th, Friday, 11:00AM 

Bldg. 38A, B2 Library

 

TITLE: 

Comparative genomic analysis of transcriptional regulatory networks in bacteria.

 

SPEAKER: 

Dmitry A. Rodionov, PhD

Burnham Institute for Medical Research, La Jolla, CA, and 

Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia

 

The comparative genomics of microbial transcriptional regulatory networks (TRNs) is an emerging field of research.
 Combining identification of orthologous transcription factors (TFs) with the genome-scale search for their cognate 
DNA-binding sites (TFBSs) is a powerful approach to the analysis of co-evolution of TFs and TFBSs. This integrated 
approach allows us to describe many various regulons controlling central metabolic pathways in bacteria. This substantial 
amount of data accumulated is a basis for understanding of the most common types of events associated with the evolution 
of TRNs in bacteria. Duplications and losses of TFs and their TFBSs result in regulon expansions, shrinkages, mergers, 
and split-ups. New regulons could be born by duplication and specialization of a TF paralog. Similarly to metabolic enzymes, 
microbial TFs are subject to horizontal gene transfer and nonorthologous gene displacement events leading to considerable 
rewiring of TRNs. Several examples of remarkable variability of TRNs associated with a particular metabolic pathway will
 be given in this overview. First, I will show that many aspects of metabolic regulation in Shewanella species are substantially 
different from regulatory network models described in E. coli. Second, I will briefly describe identification of three novel 
regulons for control of NAD metabolic pathways in bacteria, demonstrating significant variability in regulatory strategies.

 

Please let me know if you would like to meet with the speaker.