9316694 Lopilato Genes are expressed or transcribed using a complex of proteins called the transcriptional apparatus which requires access to DNA. However, DNA is highly compacted by histone proteins. To investigate how DNA structure affects gene expression, this project utilizes the bgl operon, a set of genes found in Escherichia coli. Changes in DNA structure result in bgl expression. When the bgl operon is expressed, the bacterial cell can utilize beta-glucoside sugars. However, the bgl operon is silent in wild-type cells, and therefore the cells cannot utilize these sugars. A variety of mutations cause the bgl operon to be expressed, including mutations that affect proteins involved in twisting or supercoiling the DNA. Mutations that affect the histone-like protein H-NS result in bgl expression. The goal of a genetic approach in analyzing bgl expression is to identify all the genes and gene product involved in the expression and the regulation of this operon. To this end, I have isolated a new regulatory gene, bglJ. A mutation in this gene results in bgl expression. My specific aims are to characterize and to analyze the mechanism of the bglJ gene. Characterization of bglJ will reveal whether bglJ encodes a novel histone-like protein. %%% Studying bglJ expression may lead to better understanding of how DNA structure affects gene expression in bacteria. ***
