title: Molecular cloning and expression of a thermostable xylose (glucose) isomerase gene, xylA, from Streptomyces chibaensis J-59.
abstract: In the present study, the xylA gene encoding a thermostable xylose (glucose) isomerase was cloned from Streptomyces chibaensis J-59. The open reading frame of xylA (1167 bp) encoded a protein of 388 amino acids with a calculated molecular mass of about 43 kDa. The XylA showed high sequence homology (92% identity) with that of S. olivochromogenes. The xylose (glucose) isomerase was expressed in Escherichia coli and purified. The purified recombinant XylA had an apparent molecular mass of 45 kDa, which corresponds to the molecular mass calculated from the deduced amino acid and that of the purified wild-type enzyme. The N-terminal sequences (14 amino acid residues) of the purified protein revealed that the sequences were identical to that deduced from the DNA sequence of the xylA gene. The optimum temperature of the purified enzyme was 85 degrees C and the enzyme exhibited a high level of heat stability.
authors.affiliation: Institute of Agricultural Science & Technology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Gil-Jae
authors.initials: GJ
authors.lastname: Joo
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Shin
authors.forename: Gun-Young
authors.initials: GY
authors.lastname: Heo
authors.forename: Young-Mog
authors.initials: YM
authors.lastname: Kim
authors.forename: In-Koo
authors.initials: IK
authors.lastname: Rhee
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics*; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D011994:Recombinant Proteins; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase