Abstract
We report the development of the orthogonal amber-suppressor pair Archaeoglobus fulgidus seryl-tRNA (Af-tRNA(Ser))/Methanosarcina mazei seryl-tRNA synthetase (MmSerRS) in Escherichia coli. Furthermore, the crystal structure of MmSerRS was solved at 1.45 Å resolution, which should enable structure-guided engineering of its active site to genetically encode small, polar noncanonical amino acids (ncAAs).