The structure of FemXWv in complex with a peptidyl-RNA conjugate: Mechanism of aminoacyl transfer from Ala-tRNA^Ala to peptidoglycan precursors

To gain insight into the catalytic mechanism of non-ribosomal amino acid transferases, peptidyl-RNA conjugates were synthesized for co-crystallization with FemXWv of Weissella viridescens, which transfers L-Ala from Ala-tRNAAla to the peptidoglycan precursor UDP-MurNAc-pentapeptide. The structure of the resulting complex and mutational studies revealed the mechanism by which FemXWv binds its substrates for substrate-assisted catalysis and stabilization of the tetrahedral intermediate. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.