The malate dehydrogenase gene from Botryococcus braunii (Chlorophyta, Chlorophyceae): Cloning, sequence analysis, and expression in Escherichia coli

The gene for malate dehydrogenase from Botryococcus braunii Kutzing (Chloro phyceae) was isolated, The gene codes for a protein of 316 amino acids with a calculated molecular weight of 32.9 kDa, In the N-terminal region, a pyr idine nucleotide-binding domain was observed, The G+C content of the gene i s 65%, Six copies of the (A/G)GGCGG hexanucleotide, which forms the core bi nding site for the cellular transcription factor Sp1, were observed in the promoter region, Southern blot analysis showed that malate dehydrogenase is encoded by a single gene in B. braunii, Escherichia coli cells in which th e B, braunii gene was expressed showed 3.6 times more activity in the conve rsion of oxaloacetate to malate than the noninduced ones, confirming the id entity of the gene, Botryococcus braunii malate dehydrogenase has been subj ected to phylogenetic analyses by the neighbor-joining and parsimony proced ures.