Effect of Polar Amino Acid Residue Substitution by Site-Directed Mutagenesis in the N-terminal Domain of Pseudomonas sp. Phytase on Enzyme Activity

J Microbiol Biotechnol. 2020 Jul 28;30(7):2003-3020. doi: 10.4014/jmb.2003.03020.

Abstract

The N-terminal domain of the Pseudomonas sp. FB15 phytase increases low-temperature activity and catalytic efficiency. In this study, the 3D structure of the N-terminal domain was predicted and substitutions for the amino acid residues of the region assumed to be the active site were made. The activity of mutants, in which alanine (A) was substituted for the original residue, was investigated at various temperatures and pH values. Significant differences in enzymatic activity were observed only in mutant E263A, suggesting that the amino acid residue at position 263 of the N-terminal domain is important in enzyme activity.

Keywords: Beta-propeller phytase; alkaline phytase; phytate; site-directed mutagenesis.

MeSH terms

  • 6-Phytase / chemistry
  • 6-Phytase / genetics*
  • 6-Phytase / metabolism*
  • Amino Acid Substitution*
  • Amino Acids
  • Bacterial Proteins
  • Catalysis
  • Catalytic Domain
  • Endopeptidases
  • Enzyme Stability
  • Hydrogen-Ion Concentration
  • Mutagenesis, Site-Directed*
  • Phytic Acid / metabolism
  • Protein Conformation
  • Pseudomonas / enzymology*
  • Pseudomonas / genetics*
  • Pseudomonas / metabolism
  • Temperature

Substances

  • Amino Acids
  • Bacterial Proteins
  • Phytic Acid
  • 6-Phytase
  • Endopeptidases
  • alkaline protease