Molecular cloning, sequencing, and heterologous expression of a novel zinc-containing ferredoxin gene from a thermoacidophilic Archaeon Sulfolobus sp. strain 7.
The gene encoding a novel zinc-containing ferredoxin from a hyperthermophilic and acidophilic archaeon (archaebacterium) Sulfolobus sp. strain 7 was cloned and sequenced. The DNA sequence predicts a 103 residue protein after removal of N-terminal methionine, which is in good agreement with the results of the protein analysis. Surprisingly, the residues responsible for binding a zinc atom were conserved among three other thermoacidophilic archaea. A common sequence stretch VXGXHXGHX8-17PXXLGXHGTX38-56KXDPV is proposed as a new zinc-binding motif, where three histidines and an aspartic acid are ligated to a zinc atom. The ferredoxin gene was expressed in Eschericia coli. The recombinant ferredoxin was indistinguishable from the protein purified from Sulfolobus sp. strain 7 cells by several criteria so far investigated except that the methylation of the 29th lysine was suppressed.
Wakagi
T
T
Department of Life Science, Tokyo Institute of Technology, Yokahama, Japan. atwakag@hongo.ecc.u-tokyo.ac.jp
Fujii
T
T
Oshima
T
T
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D005288:Ferredoxins / Q000737:chemistry / Q000235:genetics*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D016944:Sulfolobus / Q000235:genetics*; D015032:Zinc / Q000032:analysis*
D004269:DNA, Bacterial; D005288:Ferredoxins; D015032:Zinc