Identification and Elucidation of Uncharacterized Genes Regulated by E. coli FlhD/C

Rhonda T. Fleming, Birgit Pruess, Ph.D., Philip Matsumura, Ph.D.

Department of Microbiology and Immunology
University of Illinois at Chicago
Chicago, Illinois 60612

FlhD/C have previously been identified and characterized as a regulator of the flagellar operon. Recent studies have shown that there are also non-flagella targets of FlhD/C. By using genomic array technology, we were able to determine that FlhD/C is a global regulator and also have effects on numerous uncharacterized genes in Escherichia coli K-12. In efforts to learn more about the E. coli system and the regulation of its genes, we wanted to determine the role of a few of the unknown genes, identified as regulated by FlhD/C through this genomic array technology. To confirm the regulation of the unknown or uncharacterized genes by FlhD/C, we use reporter gene fusions and detection of mRNA levels of four unknowns in wild type and FlhD/C mutant backgrounds. The non-flagellar genes we are presently confirming and characterizing are yadC, ybeF, yihQ and yhcM. yadC genes have a putative role in pilin structure and assembly. The ybeF gene is a putative transcriptional regulator, yihQ is a putative alpha-galactosidase, and yhcM is a putative ATP binding protein or ATPase. By mutagenesis studies and structure/function studies, we want to characterize the role of these unknown genes in the E. coli system.