CLONING, SEQUENCING, AND CHARACTERIZATION OF THE FTSZ GENE FROM CORYNEFORM BACTERIA

Taking advantage of highly conserved domains present in the ftsZ genes from Escherichia coli, Rhizobium meliloti, and Bacillus subtilis, we designed degenerate oligonucleotides (oligos) corresponding to these r egions. These oligos were used as primers in PCR in order to amplify D NA sequences from Brevibacterium flavum MJ233 chromosomal DNA. The PCR product was used as a probe to recover genomic fragments from a lambd a library of Br. flavum MJ233. The complete nucleotide sequence (nt) o f the cloned 4.2-kb EcoRI fragment containing the ftsZ homolog from Br . flavum MJ233 indicated that the deduced gene product of the Br. flav um ftsZ homolog is composed of 438 amino acids (aa) with a deduced mol ecular weight of 46.9 kDa. This size of molecular weight was also conf irmed by the in vitro protein synthesis assay. Comparison of this aa s equence to the corresponding sequences from E. coli, Rh. meliloti, B. subtilis, and Streptomyces coelicolor revealed a high degree of conser vation and suggested that the Br. flavum ftsZ homolog has a putative G TP binding motif and a GTP hydrolizing region. Expression of Br. flavu m ftsZ gene in E. coli, JM109 inhibited its cell division, leading to filamentation. This suggested that the Br, flavum ftsZ product compete d with the E. coli ftsZ product. (C) 1997 Academic Press.