Molecular cloning and characterization of a novel acetylalginate esterase gene in alg operon from Sphingomonas sp. MJ-3

Appl Microbiol Biotechnol. 2014 Mar;98(5):2145-54. doi: 10.1007/s00253-013-5126-0. Epub 2013 Jul 30.

Abstract

A novel acetylalginate esterase (AcAlgE) gene was cloned and characterized from the genomic DNA library of Sphingomonas sp. MJ-3. A putative gene encoding AcAlgE protein of 292-residue precursor protein with 20-amino acid signal peptide was identified in the alg operon. The deduced AcAlgE protein has GDSL-like consensus motif and shares a highest sequence identity (51%) with GDSL family lipolytic protein from Pseudoxanthomonas suwonensis. Enzymatic assays with bacterial acetylalginate as the substrate showed that the recombinant AcAlgE protein possesses deacetylation activity. The optimal temperature and pH for the AcAlgE were 22 °C and pH 6.5 (citrate buffer), respectively. The recombinant AcAlgE protein catalyzed deacetylation of acetylalginate with release of acetate. The resulting de-acetylated alginate was readily degraded by alginate lyases, indicating that the recombinant AcAlgE enhanced the subsequent degradation of acetylalginate by alginate lyases. The recombinant AcAlgE can play an important role in the degradation of acetylated alginate such as mucoidal acetylalginate in cystic fibrosis patient.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / metabolism
  • Alginates / metabolism*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Cloning, Molecular
  • Enzyme Stability
  • Esterases / chemistry
  • Esterases / genetics
  • Esterases / isolation & purification
  • Esterases / metabolism*
  • Gene Expression
  • Glucuronic Acid / metabolism
  • Hexuronic Acids / metabolism
  • Hydrogen-Ion Concentration
  • Molecular Sequence Data
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Sphingomonas / enzymology*
  • Sphingomonas / genetics
  • Temperature

Substances

  • Acetates
  • Alginates
  • Bacterial Proteins
  • Hexuronic Acids
  • Recombinant Proteins
  • Glucuronic Acid
  • Esterases

Associated data

  • GENBANK/JQ793790