Submitted to: DNA and Cell Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2003
Publication Date: 2/1/2004
Citation: Zhao, Y., Hammond, R., Lee, I., Roe, B., Lin, S., Davis, R.E. Cell division gene cluster in spiroplasma kunkelii: functional characterization of ftsz and the first report of ftsa in mollicutes. DNA and Cell Biology. 23(2):127-134.
Interpretive Summary: Spiroplasma kunkelii is a minute phytopathogenic bacterium that has a helical cell shape and lacks a cell wall. It causes the disease known as corn stunt, which is a major limiting factor in corn production in the Americas. As part of work to understand S. kunkelii pathogenesis, we initiated this study to gain knowledge of the pathogen's growth and cell division. This paper reports results from molecular identification and functional characterization of a key genetic component that may control the process of cell multiplication in S. kunkelii. We report that a major cell division gene of S. kunkelii is remarkably similar to the cell division genes of walled bacteria, and we report the functional analyses of the gene in cells of the walled bacterium, Escherichia coli. This is the first study of a cell division gene and its product from a plant invading bacterium that lacks a cell wall. The findings will be of greatest interest to research scientists and students of microbiology and plant pathology.
Technical Abstract: The ftsZ gene, found in representatives of all bacterial groups, encodes an essential protein engaged in prokaryotic cell division. We cloned and characterized the ftsZ homologue (ftsZsk) from a pathogenic strain of the wall-less bacterium Spiroplasma kunkelii that causes corn stunt disease. The 1236-bp open reading frame of ftsZsk is capable of encoding a protein with a calculated molecular mass of 44.1 kDa. Protein sequence alignment revealed that FtsZsk is remarkably similar to FtsZ proteins from other eubacteria and possesses the conserved GTP-binding and hydrolyzing motifs. We demonstrated that overexpression of ftsZsk in E. coli causes transgression of cell division of the host cells, causing a filamentous phenotype; however, moderate expression of the ftsZsk gene can partially complement the temperature-sensitive defect of an E. coli ftsZ mutant. To our knowledge, this is the first study of a cell division gene and its product from a phytopathogenic mollicute.