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The Mouse PNGase-HR23 Complex Reveals a Complete Remodulation of the Protein-Protein Interface Compared to its Yeast Orthologs
Structural highlights
FunctionNGLY1_MOUSE Specifically deglycosylates the denatured form of N-linked glycoproteins in the cytoplasm and assists their proteasome-mediated degradation. Cleaves the beta-aspartyl-glucosamine (GlcNAc) of the glycan and the amide side chain of Asn, converting Asn to Asp. Prefers proteins containing high-mannose over those bearing complex type oligosaccharides. Can recognize misfolded proteins in the endoplasmic reticulum that are exported to the cytosol to be destroyed and deglycosylate them, while it has no activity toward native proteins. Deglycosylation is a prerequisite for subsequent proteasome-mediated degradation of some, but not all, misfolded glycoproteins.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPeptide N-glycanase removes N-linked oligosaccharides from misfolded glycoproteins as part of the endoplasmic reticulum-associated degradation pathway. This process involves the formation of a tight complex of peptide N-glycanase with Rad23 in yeast and the orthologous HR23 proteins in mammals. In addition to its function in endoplasmic reticulum-associated degradation, HR23 is also involved in DNA repair, where it plays an important role in damage recognition in complex with the xeroderma pigmentosum group C protein. To characterize the dual role of HR23, we have determined the high resolution crystal structure of the mouse peptide N-glycanase catalytic core in complex with the xeroderma pigmentosum group C binding domain from HR23B. Peptide N-glycanase features a large cleft between its catalytic cysteine protease core and zinc binding domain. Opposite the zinc binding domain is the HR23B-interacting region, and surprisingly, the complex interface is fundamentally different from the orthologous yeast peptide N-glycanase-Rad23 complex. Different regions on both proteins are involved in complex formation, revealing an amazing degree of divergence in the interaction between two highly homologous proteins. Furthermore, the mouse peptide N-glycanase-HR23B complex mimics the interaction between xeroderma pigmentosum group C and HR23B, thereby providing a first structural model of how the two proteins interact within the nucleotide excision repair cascade in higher eukaryotes. The different interaction interfaces of the xeroderma pigmentosum group C binding domains in yeast and mammals suggest a co-evolution of the endoplasmic reticulum-associated degradation and DNA repair pathways. Structure of the mouse peptide N-glycanase-HR23 complex suggests co-evolution of the endoplasmic reticulum-associated degradation and DNA repair pathways.,Zhao G, Zhou X, Wang L, Li G, Kisker C, Lennarz WJ, Schindelin H J Biol Chem. 2006 May 12;281(19):13751-61. Epub 2006 Feb 24. PMID:16500903[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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