It is generally accepted that chloroplast was originated from a photosynthetic cyanobacterium by endosymbiosis. Recent findings indicated that a FtsZ like protein, which was the homologue of the essential prokaryotic cell division protein, involved in the division of chloroplasts in plants. Using degenerate oligodeoxyribonucleotide primers based on conserved regions of the prokaryotic cell division protein FtsZ, a 570?bp cDNA fragment, named CrFtsZ 2, was isolated from Chlamydomonas reinhardtii by RT PCR. It was used to search the Chlamydomonas reinhardtii EST Database, and several contig EST sequences were found. The complete CrFtsZ 2 cDNA sequence was assembled by software and was amplified by RT PCR. With a 1?305?bp ORF(opening reading frame), the full length 1?815?bp CrFts Z cDNA had a 19?bp 5′UTR and a 490?bp 3′UTR. The CrFtsZ 2, which showed significant homology with other FtsZs , was a typical FtsZ gene, and encoded a precursor of 434 amino acid residues with a putative transit peptide in its N terminal. Phylogenetic tree of 23 FtsZs homologies reconstructed based on 300 conserved amino acid regions of the FtsZs suggested that CrFtsZ2 shared an ancestor probably with the FtsZ in cyanobacteria.
