Expression, purification, characterization and crystallization of flap endonuclease-1 from Methanococcus jannaschii

A gene coding for a protein homologous to the flap endonuclease-1 (FEN-1) w as cloned from Methanococcus jannaschii, overexpressed, purified and charac terized. The gene product from M. jannaschii shows 5' endo-/exonuclease and 5' pseudo-Y-endonuclease activities as observed in the FEN-1 in eukaryotes . In addition, Methanococcus jannaschii FEN-I functions effectively at high concentrations of salt, unlike eukaryotic FEN-1, We have crystallized Meth anococcus jannaschii FEN-1 and analyzed its preliminary character. The crys tal belongs to the space group of P2(1) with unit cell dimensions of a = 58 .93 Angstrom, b = 42.53 Angstrom, c = 62.62 Angstrom and beta = 92.25 degre es, A complete data set has been collected at 2.0 Angstrom resolution using a frozen crystal.