Cloning, expression and characterization of a novel cold‑adapted GDSL family esterase from Photobacterium sp. strain J15

Extremophiles. 2016 Jan;20(1):44-55. doi: 10.1007/s00792-015-0796-4.

Abstract

The gene encoding for a novel cold-adapted enzyme from family II of bacterial classification (GDSL family) was cloned from the genomic DNA of Photobacterium sp. strain J15 in an Escherichia coli system, yielding a recombinant 36 kDa J15 GDSL esterase which was purified in two steps with a final yield and purification of 38.6 and 15.3 respectively. Characterization of the biochemical properties showed the J15 GDSL esterase had maximum activity at 20 °C and pH 8.0, was stable at 10 °C for 3 h and retained 50 % of its activity after a 6 h incubation at 10 °C. The enzyme was activated by Tween-20, -60 and Triton-X100 and inhibited by 1 mM Sodium dodecyl sulphate (SDS), while β-mercaptoethanol and Dithiothreitol (DTT) enhanced activity by 4.3 and 5.4 fold respectively. These results showed the J15 GDSL esterase was a novel cold-adapted enzyme from family II of lipolytic enzymes. A structural model constructed using autotransporter EstA from Pseudomonas aeruginosa as a template revealed the presence of a typical catalytic triad consisting of a serine, aspartate, and histidine which was verified with site directed mutagenesis on active serine.

MeSH terms

  • Acclimatization*
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Carboxylic Ester Hydrolases / chemistry
  • Carboxylic Ester Hydrolases / genetics
  • Carboxylic Ester Hydrolases / metabolism*
  • Cold Temperature*
  • Enzyme Stability
  • Molecular Sequence Data
  • Photobacterium / enzymology*
  • Photobacterium / genetics
  • Phylogeny

Substances

  • Bacterial Proteins
  • Carboxylic Ester Hydrolases