2dps
From Proteopedia
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Structure of Leucyl/phenylalanyl-tRNA-protein transferase
Overview
Eubacterial leucyl/phenylalanyl-tRNA protein transferase (L/F-transferase), encoded by the aat gene, conjugates leucine or phenylalanine to the N-terminal Arg or Lys residue of proteins, using Leu-tRNA(Leu) or Phe-tRNA(Phe) as a substrate. The resulting N-terminal Leu or Phe acts as a degradation signal for the ClpS-ClpAP-mediated N-end rule protein degradation pathway. Here, we present the crystal structures of Escherichia coli L/F-transferase and its complex with an aminoacyl-tRNA analog, puromycin. The C-terminal domain of L/F-transferase consists of the GCN5-related N-acetyltransferase fold, commonly observed in the acetyltransferase superfamily. The p-methoxybenzyl group of puromycin, corresponding to the side chain of Leu or Phe of Leu-tRNA(Leu) or Phe-tRNA(Phe), is accommodated in a highly hydrophobic pocket, with a shape and size suitable for hydrophobic amino-acid residues lacking a branched beta-carbon, such as leucine and phenylalanine. Structure-based mutagenesis of L/F-transferase revealed its substrate specificity. Furthermore, we present a model of the L/F-transferase complex with tRNA and substrate proteins bearing an N-terminal Arg or Lys.
About this Structure
2DPS is a Single protein structure of sequence from Escherichia coli. Active as Leucyltransferase, with EC number 2.3.2.6 Full crystallographic information is available from OCA.
Reference
Crystal structures of leucyl/phenylalanyl-tRNA-protein transferase and its complex with an aminoacyl-tRNA analog., Suto K, Shimizu Y, Watanabe K, Ueda T, Fukai S, Nureki O, Tomita K, EMBO J. 2006 Dec 13;25(24):5942-50. Epub 2006 Nov 16. PMID:17110926
Page seeded by OCA on Thu Feb 21 17:01:26 2008
