title: Squalene-hopene cyclase (Spterp25) from Streptomyces peucetius: sequence analysis, expression and functional characterization.
abstract: Squalene-hopene cyclase, which catalyzes the complex cyclization of squalene to the pentacyclic triterpene, hopene, is a key enzyme in the biosynthesis of hopanoids. The deduced amino acid sequence of the Streptomyces peucetius gene (spterp25) had significant similarity to other prokaryotic squalene-hopene cyclases. Like other triterpene cyclases, the S. peucetius squalene-hopene cyclase contains eight so-called QW-motifs with an aspartate-rich domain. The 2,025-bp squalene-hopene cyclase-encoding gene was expressed in Escherichia coli BL21(DE3)pLySs, and the in vitro activity of the recombinant cyclase was demonstrated using purified membrane protein. The cyclization product hopene was identified by gas chromatography/mass spectrometry (GC/MS).
authors.affiliation: Department of Pharmaceutical Engineering, Institute of Biomolecule Reconstruction (IBR), Sun Moon University, #100 Kalsan-ri, Tangjeong-myeon, Asansi, Chungnam 336-708, South Korea.
authors.forename: Gopal Prasad
authors.initials: GP
authors.lastname: Ghimire
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Oh
authors.forename: Hei Chan
authors.initials: HC
authors.lastname: Lee
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Sohng
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D019751:Intramolecular Transferases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013185:Squalene / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology*; D014315:Triterpenes / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D014315:Triterpenes; C028765:diploptene; D013185:Squalene; D019751:Intramolecular Transferases; C066630:squalene-hopene cyclase