The Molecular Basis for the Post-Translational Addition of Amino Acids by L/F Transferase in the N-End Rule Pathway

Author(s): Angela Wai S. Fung, Richard P. Fahlman

Journal Name: Current Protein & Peptide Science

Volume 16 , Issue 2 , 2015

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Graphical Abstract:


The N-end rule pathway is a conserved targeted proteolytic process observed in organisms ranging from eubacteria to mammals. The N-end rule relates the metabolic stability of a protein to its N-terminal amino acid residue. The identity of the N-terminal amino acid residue is a primary degradation signal, often referred to as an N-degron, which is recognized by the components of the N-end rule when it is a destabilizing N-terminus. N-degrons may be exposed by non-processive proteolytic cleavages or by post-translational modifications. One modification is the post-translational addition of amino acids to the N-termini of proteins, a reaction catalyzed by aminoacyl-tRNA protein transferases. The aminoacyl-tRNA protein transferase in eubacteria like Escherichia coli is L/F transferase. Recent investigations have reported unexpected observations regarding the L/F transferase catalytic mechanism and its mechanisms of substrate recognition. Additionally, recent proteome-wide identification of putative in vivo substrates facilitates hypothesis into the yet elusive biological functions of the prokaryotic N-end rule pathway. Here we summarize the recent findings on the molecular mechanisms of catalysis and substrate recognition by the E. coli L/F transferase in the prokaryotic N-end rule pathway.

Keywords: aa-tRNA, Dupli-GNAT superfamily, L/F transferase, N-end rule, non-ribosomal peptide bond formation, posttranslational addition of amino acid.

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Article Details

Year: 2015
Published on: 15 February, 2015
Page: [163 - 180]
Pages: 18
DOI: 10.2174/1389203716666150112095726
Price: $65

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