Molecular Cloning and Gene Expression Analysis of Tomato Endo-β-N-acetylglucosaminidase, an Endoglycosidase Involved in the Production of High-Mannose Type Free N-Glycans during Tomato Fruit Ripening

Abstract

In this study, we identified a gene encoding tomato ENGase (Endo-LE) using the gene information of rice ENGase, and expressed the Endo-LE protein in Escherichia coli. The substrate specificity of the recombinant Endo-LE was the same as that of the native enzyme, showing strong activity towards the high-mannose type N-glycans with the Manα1-2Manα1-3Manβ1-4GlcNAcβ1-4GlcNAc unit. Real-time PCR analysis revealed that the gene expression of Endo-LE did not vary significantly with the tomato ripening process, indicating that Endo-LE activity is ubiquitously expressed.