Kendrick 9724038 To deposit a septum at the correct time in the cell cycle and at the correct location, a unicellular bacterium must be able to monitor the completion of DNA replication and the segregation of the newly replicated DNA, locate the center of the cell, and initiate the centripetal growth of new cell wall and cytoplasmic membrane. Because binary fission is the only means by which most commonly studied bacteria reproduce, many of the genes required for cell division are essential and thus cannot be readily dissected by mutation analysis. Unlike other bacteria, Streptomyces grows as branched, filamentous, multinucleoidal cells that undergo multiple septation events to form chains of spores. Key events in Streptomyces differentiation include the massive and relatively synchronous septation necessary to form the compartments destined to become the spores, and the extensive growth of the differentiated structures prior to septation. To identify structural, enzymatic, and regulatory proteins responsible for this dramatic change in cell structure, this project focuses on two proteins required for sporulation septum formation: FtsZ and the septum-specific penicillin-binding protein. These experiments will identify the factors involved in the developmental regulation of ftsZ in Streptomyces griseus by using an integrative reporter system, mutant analysis, and the analysis of proteins required for transcription of ftsZ. The gene encoding the septum-specific penicillin-binding protein of S.griseus will be isolated and its nucleotide sequence determined; in another experiment this gene will be disrupted to confirm its role in septum formation. Cell division is an essential property of all organisms. To reproduce, each cell must divide to generate viable daughter cells. The analysis of cell division in filamentous bacteria is a logical system to use to study molecular events central to the correct timing and location of cell division. By characterizing the cell division machine ry in these bacteria, this research will help to build the cornerstones of cell growth.
