Novel medium-chain prenyl diphosphate synthase from the thermoacidophilic archaeon Sulfolobus solfataricus.
Two open reading frames which encode the homologues of (all-E) prenyl diphosphate synthase are found in the whole-genome sequence of Sulfolobus solfataricus, a thermoacidophilic archaeon. It has been suggested that one is a geranylgeranyl diphosphate synthase gene, but the specificity and biological significance of the enzyme encoded by the other have remained unclear. Thus, we isolated the latter by the PCR method, expressed the enzyme in Escherichia coli cells, purified it, and characterized it. The archaeal enzyme, 281 amino acids long, is highly thermostable and requires Mg(2+) and Triton X-100 for full activity. It catalyzes consecutive E-type condensations of isopentenyl diphosphate with an allylic substrate such as geranylgeranyl diphosphate and yields the medium-chain product hexaprenyl diphosphate. Despite such product specificity, phylogenetic analysis revealed that the archaeal medium-chain prenyl diphosphate synthase is distantly related to the other medium- and long-chain enzymes but is closely related to eucaryal short-chain enzymes.
Hemmi
Hisashi
H
Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba-yama 07, Sendai, Miyagi 980-8579, Japan.
Ikejiri
Satoru
S
Yamashita
Satoshi
S
Nishino
Tokuzo
T
D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D019143:Evolution, Molecular; D019766:Genes, Archaeal; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D016944:Sulfolobus / Q000201:enzymology / Q000235:genetics*; D013729:Terpenes / Q000378:metabolism
D019843:Archaeal Proteins; D011994:Recombinant Proteins; D013729:Terpenes; D019883:Alkyl and Aryl Transferases; C036826:trans-pentaprenyltranstransferase