Cloning And Analysis Of FtsZ CDNAs In Nicotiana Tabacum And Their Expression In E.coli

Two cDNAs (NtFtsZl and NtFtsZ2) encoding the prokaryotic cell division protein FtsZ homologoues have been isolated from Nicotiana tobaccum by reverse transcription polymerase chain reaction(RT-PCR) . Protein sequence alignments indicate that the two NtFtsZs are similar to other FtsZ proteins and contain the conserved GTP binding motif. NtFtsZs also show a typical N-terminal extension conserved just in Plant FtsZs.Sequence data alignmented with the higher plants suggest that the two NtFtsZs are the members of FtsZl family. Analysis of plastid transit peptide suggest that the two tobacco FtsZs both contain the plastid transit peptide at their N-terminal. Prediction of plastid transit peptide and phyiogenetic analysis based on the ammoniac acids sequences all support the assumption. These results may indicate that the existence of a more complicated plastid division model in higher plants.In order to determine whether the cloned NtftZs exhibited biological activity, we assayed the effects of the cloned genes on E.coli cells. Overexpression of the NtFtsZs-GST fusion proteins in E.coli also resulted in filamentous phenotype that is similar to the phenotype of EcFtsZ mutants. These results suggest that NtFtsZs can recognize the signals for division site positioning in bacteria and can interact with the bacterial division machinery.