Mutant SepRS, and method for site-specific introduction of phosphoserine into protein using the same

摘要

A mutant SepRS which is suitable for a site-specific introduction of phosphoserine into a protein is prepared by analyzing the structure and functions of a phosphoseryl-tRNA synthetase (SepRS) derived from an archaebacterium. A mutant SepRS composed of an amino acid sequence depicted in SEQ ID NO:2, in which any one or more of glutamic acids at position-418 and position-420 and threonine at position-423 are substituted with other amino acid, and having enhanced binding affinity with a suppressor tRNA as compared with a wild type phosphoseryl-tRNA synthetase (SepRS) composed of an amino acid sequence depicted in SEQ ID NO:2 is provided.