These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cloning and characterization of a novel L-arabinose isomerase from Bacillus licheniformis.
    Author: Prabhu P, Tiwari MK, Jeya M, Gunasekaran P, Kim IW, Lee JK.
    Journal: Appl Microbiol Biotechnol; 2008 Nov; 81(2):283-90. PubMed ID: 18716768.
    Abstract:
    Based on analysis of the genome sequence of Bacillus licheniformis ATCC 14580, an isomerase-encoding gene (araA) was proposed as an L-arabinose isomerase (L-AI). The identified araA gene was cloned from B. licheniformis and overexpressed in Escherichia coli. DNA sequence analysis revealed an open reading frame of 1,422 bp, capable of encoding a polypeptide of 474 amino acid residues with a calculated isoelectric point of pH 4.8 and a molecular mass of 53,500 Da. The gene was overexpressed in E. coli, and the protein was purified as an active soluble form using Ni-NTA chromatography. The molecular mass of the purified enzyme was estimated to be approximately 53 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 113 kDa by gel filtration chromatography, suggesting that the enzyme is a homodimer. The enzyme required a divalent metal ion, either Mn(2+)or Co(2+), for enzymatic activity. The enzyme had an optimal pH and temperature of 7.5 and 50 degrees C, respectively, with a k (cat) of 12,455 min(-1) and a k (cat)/K (m) of 34 min(-1) mM(-1) for L-arabinose, respectively. Although L-AIs have been characterized from several other sources, B. licheniformis L-AI is distinguished from other L-AIs by its wide pH range, high substrate specificity, and catalytic efficiency for L-arabinose, making B. licheniformis L-AI the ideal choice for industrial applications, including enzymatic synthesis of L-ribulose. This work describes one of the most catalytically efficient L-AIs characterized thus far.
    [Abstract] [Full Text] [Related] [New Search]