Cloning, expression, and characterization of a highly active alkaline pectate lyase from alkaliphilic Bacillus sp. N16-5.

Abstract

An alkaline pectate lyase, Bsp165PelA, was purified to homogeneity from the culture broth of alkaliphilic Bacillus sp. N16-5. The enzyme showed a specific activity as high as 1000 U/mg and had optimum activity at pH 11.5 and 50 degrees . It was composed of a single polypeptide chain with a molecular of 42 kDa deduced from SDS-PAGE, and its isoelectric point was around pH 6.0. It could efficiently depolymerize polygalacturonate and pectin. Characterization of product formation revealed unsaturated digalacturonate and trigalacturonate as the main product. The pectate lyase gene (pelA) contained an open reading frame (ORF) of 1089 bp, encoding a 36-amino acids signal peptide and a mature protein of 326 amino acids with a calculated molecular mass of 35.943 Da. The deduced amino acid sequence from the pelA ORF exhibited significant homology to those of known pectate lyases in polysaccharide lyase family 1. Some conserved active-site amino acids were found in the deduced amino acid sequence of Bsp165PelA. Ca2+ was not required for activity on pectic substrates.

• Authors: Gang Li, Lang Rao, Yanfen Xue, Cheng Zhou, Yun Zhang, Yanhe Ma
• Journal: Journal of microbiology and biotechnology (J Microbiol Biotechnol) Vol. 20 Issue 4 Pg. 670-7 (Apr 2010) ISSN: 1017-7825 [Print] Korea (South)
• PMID: 20467237 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Bacterial
• Pectins
• Polysaccharide-Lyases
• pectate lyase
• polygalacturonic acid

Topics

• Amino Acid Sequence
• Bacillus (enzymology, genetics)
• Base Sequence
• Cloning, Molecular
• DNA, Bacterial (chemistry, genetics)
• Hydrogen-Ion Concentration
• Kinetics
• Molecular Sequence Data
• Pectins (metabolism)
• Polymerase Chain Reaction
• Polysaccharide-Lyases (biosynthesis, genetics, isolation & purification, metabolism)