CLONING AND SEQUENCE OF FTSZ AND FLANKING REGIONS FROM THE CYANOBACTERIUM ANABAENA PCC-7120

Using degenerate oligodeoxyribonucleotide primers based on conserved r egions of the cell-division protein FtsZ, a 220-bp fragment of DNA was amplified by the polymerase chain reaction from Anabaena PCC 7120 (An a). This fragment, which showed significant homology with Escherichia coli ftsZ, was used as a probe to isolate a 15-kb genomic clone contai ning ftsZ from an Ana DNA library. Sequence analysis revealed an open reading frame (ORF) encoding a protein of 379 amino acids, with 49% id entity with E. coli FtsZ. Upstream of Ana ftsZ is a small, unidentifie d ORF, transcribed in the same direction. An ORF lying downstream of t he ftsZ coding region and transcribed in the opposite orientation, sho ws homology with bacterial glutathione synthetase-encoding genes. Sing le copies of ftsZ have been identified in Ana and two other cyanobacte ria. Multiple transcripts hybridising to ftsZ were detected by Norther n hybridisation.