The Exopolyphosphatase Gene from Sulfolobus solfataricus: Characterization of the First Gene Found To Be Involved in Polyphosphate Metabolism in Archaea

AUTOR(ES)

Cardona, Silvia T.

FONTE

American Society for Microbiology

RESUMO

Inorganic polyphosphate (polyP) polymers are widely distributed in all kinds of organisms. Although the presence of polyP in members of the domain Archaea has been described, at present nothing is known about the enzymology of polyP metabolism or the genes involved in this domain. We have cloned, sequenced, and overexpressed an exopolyphosphatase (PPX) gene (ppx) from thermophilic Sulfolobus solfataricus. The gene codes for a functional PPX and possesses an open reading frame for 417 amino acids (calculated mass, 47.9 kDa). The purified recombinant PPX was highly active, degrading long-chain polyP (700 to 800 residues) in vitro at 50 to 60°C. The putative PPXs present in known archaeal genomes showed the highest similarity to yeast PPXs. In contrast, informatic analysis revealed that the deduced amino acid sequence of S. solfataricus PPX showed the highest similarity (25 to 45%) to sequences of members of the bacterial PPXs, possessing all of their conserved motifs. To our knowledge, this is the first report of an enzyme characterized to be involved in polyP metabolism in members of the Archaea.

Documentos Relacionados

• The crystal structure of anthranilate synthase from Sulfolobus solfataricus: Functional implications
• 3-hydroxy-3-methylglutaryl coenzyme A reductase of Sulfolobus solfataricus: DNA sequence, phylogeny, expression in Escherichia coli of the hmgA gene, and purification and kinetic characterization of the gene product.
• Molecular Characterization of the α-Glucosidase Gene (malA) from the Hyperthermophilic Archaeon Sulfolobus solfataricus
• Cloning and Characterization of Polyphosphate Kinase and Exopolyphosphatase Genes from Pseudomonas aeruginosa 8830
• Structure and Biochemical Characterization of Protein Acetyltransferase from Sulfolobus solfataricus*