Structural insights into the mechanism of intramolecular proteolysis. |
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Authors: | Q Xu D Buckley C Guan H C Guo |
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Affiliation: | Department of Biophysics, Boston University School of Medicine, Massachusetts 02118-2526, USA. |
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Abstract: | A variety of proteins, including glycosylasparaginase, have recently been found to activate functions by self-catalyzed peptide bond rearrangements from single-chain precursors. Here we present the 1.9 A crystal structures of glycosylasparaginase precursors that are able to autoproteolyze via an N --> O acyl shift. Several conserved residues are aligned around the scissile peptide bond that is in a highly strained trans peptide bond configuration. The structure illustrates how a nucleophilic side chain may attack the scissile peptide bond at the immediate upstream backbone carbonyl and provides an understanding of the structural basis for peptide bond cleavage via an N --> O or N --> S acyl shift that is used by various groups of intramolecular autoprocessing proteins. |
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