DNA Topoisomerases I From Thermophilic Bacteria

摘要: Summary The gene encoding the DNA topoisomerase I from thermophilic bacterium Fervidobacterium islandicum has been cloned by using oligonucleotides derived internal microsequencing of purified protein ( Bouthier de la Tour et al., 1993). corresponding nucleotide sequence determined, revealing an open reading frame 2097 nucleotides. deduced amino acid (699 residues) clearly showed that belongs to E. coli TopA family, and 53% identity with Thermotoga maritima 1995). Comparison F. sequences other species revealed several interesting features: (1) a putative N-terminal tail 33 acids, whose function is unknown. (2) 8 acids insertion close active site tyrosine, shared 3 bacterial sequences. (3) unique zinc finger conserved in 7 out 9 However, no significant feature linked thermophily could distinguish two thermotogales topoisomerases their mesophilic counterparts. Finally, analysis organization vicinity locus different it was not conserved.