CHARACTERIZATION OF THE PSBA GENE FROM CHLOROPLASTS OF POPULOS DELTOIDES

A 2.9 kbp EcoRI fragment from chloroplast DNA of a tree species Populu s deltoides, has been cloned. Nucleotide sequence analysis led to the identification of a 1062 bp open reading frame located at one end of t he recombinant clone. This open reading frame has more than 94% nucleo tide sequence homology with tobacco and cotton psbA genes. The deduced amino acid sequence from poplar psbA gene is highly homologous to tob acco and differs only by 2 amino acids located at C-terminus of the pr otein. An AT rich region, capable of forming a potential stem-loop str ucture was located down stream to the psbA gene. Our Southern hybridiz ation data confirms the presence of IR region as well as the location of the psbA gene near one of the IR in P. deltoides.