Molecular cloning and expression of a thermostable xylose (glucose) isomerase gene, xylA, from Streptomyces chibaensis J-59.
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.
Joo
Gil-Jae
GJ
Institute of Agricultural Science & Technology, Kyungpook National University, Daegu 702-701, Republic of Korea.
Shin
Jae-Ho
JH
Heo
Gun-Young
GY
Kim
Young-Mog
YM
Rhee
In-Koo
IK
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
D004269:DNA, Bacterial; D011994:Recombinant Proteins; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase