Cloning and characterization of a xylanase, KRICT PX1 from the strain Paenibacillus sp. HPL-001

• Published in: Biotechnology advances 2010-09, Vol.28 (5), p.594-601
• Main Authors: Hwang, In Taek, Lim, Hee Kyung, Song, Ha Young, Cho, Soo Jin, Chang, Jong-San, Park, No-Joong
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Base Sequence; Biological and medical sciences; Biotechnology; Characterization; Cloning; Cloning, Molecular; EDTA; Electrophoresis, Polyacrylamide Gel; Encoding; Endo-1,4-beta Xylanases - chemistry; Endo-1,4-beta Xylanases - genetics; Endo-1,4-beta Xylanases - metabolism; Enzyme Stability; Escherichia coli; Escherichia coli - genetics; Fundamental and applied biological sciences. Psychology; Genes; Geobacillus; Hydrogen-Ion Concentration; Kinetics; Linear Models; Metals - chemistry; Metals - metabolism; Molecular Sequence Data; Paenibacillus; Paenibacillus - enzymology; Paenibacillus - genetics; Paenibacillus sp. HPL-001; Recombinant KRICT PX1; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Salts - chemistry; Salts - metabolism; Sequence Alignment; Similarity; Strain; Temperature; Xylanase
• ISSN: 0734-9750; 1873-1899
• DOI: 10.1016/j.biotechadv.2010.05.007

The KRICT PX1 gene (GB: FJ380951) consisting of 996 bp encoding a protein of 332 amino acids (38.1 kDa) from the recently isolated Paenibacillus sp. strain HPL-001 (KCTC11365BP) has been cloned and expressed in Escherichia coli. The xylanase KRICT PX1 showed high activity on birchwood xylan, and was active over a pH range of 5.0 to 11.0, with two optima at pH 5.5 and 9.5 at 50 °C with K m value of 5.35 and 3.23, respectively. The xylanase activity was not affected by most salts, such as NaCl, LiCl, KCl, NH 4Cl, CaCl 2, MgCl 2, MnCl 2, and CsCl 2 at 1 mM, but affected by CuSO 4, ZnSO 4, and FeCl 3. One mM of EDTA, 2-mercaptoethanol, and PMSF did not affect the xylanase activity. TLC analysis of the catalyzed products after reaction with birchwood xylan revealed that xylobiose was the major product with smaller amounts of xylotriose and xylose. A similarity analysis of the amino acids in KRICT PX1 resulted 72% identity with xylanase from Geobacillus stearothermophilus (GB: ZP_03040360), 70% identity with intracellular xylanase from an uncultured bacterium (GB: AAP51133), 68% identity with endo-1-4-xylanse from Paenibacillus sp. (GB: ZP_02847150). In addition, the amino acid alignment of KRICT PX1 with glycosyl hydralase (GH) family 10 xylanases revealed a high degree of homology in highly conserved regions including the catalytic sites, and this was confirmed through PROSITE scan. These results imply that KRICT PX1 is a new xylanase gene, and this alkaline xylanase belongs to GH family 10.