The mystery of SPO1 delayed early genes
Yip, Tameson Kay Snyder
Master of Arts
Genes of the Bacillus subtilis infecting bacteriophage SPO1 are classified as early, middle or late genes, based on which sigma factor is used for their transcription. Within the early gene category, there are two subsets of genes, immediate and delayed early (including genes 37-40), which have different temporal expression patterns. Genes 37-40 are shown involved in the shutoff of host macromolecular synthesis. Gene products (gp) 39 and 40 were shown to be lethal when expressed in E. coli cells, through an undetermined mechanism. Gp39 was purified under denaturing conditions, but could not be properly refolded. Genes 2.21, 25.1 and 51 were studied in order to understand how delayed early genes are regulated. Gp51 was partially purified. An additional gene expressed from within gene 51 was discovered. It was determined that SPO1 mutations of genes 2.21 and 25.1 could not be isolated, even when a variety of conditions were tested.