Bayer School of Natural and Environmental Sciences
Joseph R. McCormick
John S. Doctor
cell division, S. coelicolor
Streptomyces coelicolor, a gram-positive bacterium containing division genes that are dispensable for growth and viability. ftsZ encodes the earliest acting cell division protein in prokaryotes. In S. coelicolor a mutation at codon 275 in ftsZ (ftsZ25), changes an alanine to a valine causing a block in division. Using a homology model of the crystal structure of FtsZ, I hypothesized that changing another amino acid having direct interaction with amino acid 275 might restore function. The structure-directed mutation changed a leucine to a valine at codon 259. The double mutation did not restore division to the organism; this change alone also affected cell division in a negative way. Alternatively, I used two random mutagenesis approaches. One, a chemical mutagen, hydroxylamine yielded no significant results in preliminary experiments. The second way was through the use of a mutator strain form which I isolated two suppressors of ftsZ25 that partially restore division.
Ciccone, C. (2003). Isolation of Intragenic Suppressor Mutations of a Dominant-Negative ftsZ Allele (Master's thesis, Duquesne University). Retrieved from https://dsc.duq.edu/etd/413