ORGANIZATION AND NUCLEOTIDE-SEQUENCE OF THE DNA-POLYMERASE GENE FROM THE ARCHAEON PYROCOCCUS-FURIOSUS

We cloned the gene encoding the thermostable DN polymerase from the archaeon Pyrococcus furiosus The DNA fragment of 2785 base pair (bp) containing the structural gene for DNA polymerase wa sequenced. DNA polymerase (Pfu polymerase), a deduced from the DNA sequence, consisted of 77 amino acids, had a molecular weight of 90,109, and wa structurally homologous to the alpha-like DNA polymerase (family B) represented by human DNA polymerase alpha and Escherichia coli DNA polymerase II. An unrooted phylogenetic tree of the alpha-like DNA polymerases base on the amino acid sequence alignment was constructed. Pfu polymerase, with two other archaeon polymerases, constitutes a group with some anima viruses. The transcription initiation sites of the po gene were identified by analysis of in vivo transcripts of both from P. furiosus and E. coli, and the promoters were assigned upstream of the po coding region. A typical promoter sequence for the archaeon was found at reasonable distance from the transcription initiation site in P.furiosus.