𝘚𝘵𝘳𝘦𝘱𝘵𝘰𝘮𝘺𝘤𝘦𝘴 initiate a complex developmental program during their 5-day life cycle, consisting of aerial mycelium formation and antibiotic production. Several developmental genes are involved in regulating these events, one of which is 𝘣𝘭𝘥𝘉. I have complemented a 𝘣𝘭𝘥𝘉 null mutant, which demonstrated the loss of aerial mycelium formation and antibiotic production, restoring both characteristics. This demonstrated that 𝘣𝘭𝘥𝘉 is essential for 𝘚. 𝘤𝘰𝘦𝘭𝘪𝘤𝘰𝘭𝘰𝘳 morphogenesis but not viability. Using a bacterial two hybrid system devised, I screened the 𝘚. 𝘤𝘰𝘦𝘭𝘪𝘤𝘰𝘭𝘰𝘳 genome using BldB as "bait" for binding partners of BldB. The two most compelling candidates were bbpl, a homologue of UspA in 𝘌. 𝘤𝘰𝘭𝘪, and bbp2, a homologue of SrmR in 𝘚. 𝘢𝘮𝘣𝘰𝘧𝘢𝘤𝘪𝘦𝘯𝘴. Furthermore, I have investigated these interactions biochemically by affinity chromatography to further elucidate the details involved in these interactions. Preliminary results showed three protein bands obtained at approximately 68kDa, 55kDa and 35kDa, respectively. / Thesis / Master of Science (MS)

The Streptomyces are invaluable as a natural source of antibiotics and other bioactive compounds used in medicine and agriculture. S. coelicolor is the model streptomycete, and is studied for its complex secondary metabolism and multicellular life cycle. The subject of this work is bldB, a gene essential for development and antibiotic production in S. coelicolor, and one of its many homologues, located in the abaA antibiotic regulatory locus. The aim was to study the transcriptional regulation of bldB using a luminescent reporter, and investigate the role of each of the genes in the abaA cluster in regulation of antibiotic production, in order to understand the function and mechanism of action of bldB and its homologues. Individual deletion of each of the four genes in the abaA cluster resulted in varying effects on production of the antibiotic CDA. The bldB homologue, SCO0703, was shown to be a positive regulator of CDA, as the null mutant was severely defective in CDA production. It was found that bldB is expressed in most other bld developmental mutants, with the exception of bldD. There was no direct interaction observed between BldD and the bldB promoter, and possible mechanisms of indirect regulation are proposed. / Thesis / Master of Science (MSc)