Structural and Functional Studies of Transcriptional Regulation in Helicobacter pylori

Structural, biological, and phenotypic analyses of proteins that are involved in transcriptional regulation in the pathogenic bacterium Helicobacter pylori are presented. A high-resolution structure of the C-terminal domain of the á subunit of RNA polymerase, determined using nuclear magnetic resonance methods, is presented, along with a model showing species-specific differences compared to the Escherichia coli protein. The structure of the protein encoded by the HP0564 gene is also presented, suggesting that it is a novel transcriptional regulator in H. pylori. In order to determine the specific functions of HP0564 and HP0222, another novel transcriptional regulator discovered in our laboratory, several experimental approaches were used to analyze mutant strains with disrupted HP0222 or HP0564 genes. Based on results of growth and motility assays of our mutant strains, as well as microarray data, we propose that HP0222 is a regulator of motility in H. pylori and that it may play an important role in the adhesion response.