+Open data
-Basic information
Entry | Database: PDB / ID: 8vkj | |||||||||
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Title | Cryo-EM structure of human HGSNAT bound with Acetyl-CoA | |||||||||
Components | Heparan-alpha-glucosaminide N-acetyltransferase | |||||||||
Keywords | MEMBRANE PROTEIN / Lysosome / Transmembrane acetyltransferase / Acetyl-CoA / Heperan sulfate | |||||||||
Function / homology | Function and homology information heparan-alpha-glucosaminide N-acetyltransferase / heparan-alpha-glucosaminide N-acetyltransferase activity / MPS IIIC - Sanfilippo syndrome C / heparan sulfate proteoglycan catabolic process / HS-GAG degradation / lysosomal transport / acyltransferase activity / protein complex oligomerization / tertiary granule membrane / specific granule membrane ...heparan-alpha-glucosaminide N-acetyltransferase / heparan-alpha-glucosaminide N-acetyltransferase activity / MPS IIIC - Sanfilippo syndrome C / heparan sulfate proteoglycan catabolic process / HS-GAG degradation / lysosomal transport / acyltransferase activity / protein complex oligomerization / tertiary granule membrane / specific granule membrane / lysosomal lumen / lysosomal membrane / Neutrophil degranulation / plasma membrane Similarity search - Function | |||||||||
Biological species | Homo sapiens (human) | |||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.92 Å | |||||||||
Authors | Li, F. / Zhao, B. | |||||||||
Funding support | United States, 2items
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Citation | Journal: Nat Commun / Year: 2024 Title: Structural and mechanistic insights into a lysosomal membrane enzyme HGSNAT involved in Sanfilippo syndrome. Authors: Boyang Zhao / Zhongzheng Cao / Yi Zheng / Phuong Nguyen / Alisa Bowen / Robert H Edwards / Robert M Stroud / Yi Zhou / Menno Van Lookeren Campagne / Fei Li / Abstract: Heparan sulfate (HS) is degraded in lysosome by a series of glycosidases. Before the glycosidases can act, the terminal glucosamine of HS must be acetylated by the integral lysosomal membrane enzyme ...Heparan sulfate (HS) is degraded in lysosome by a series of glycosidases. Before the glycosidases can act, the terminal glucosamine of HS must be acetylated by the integral lysosomal membrane enzyme heparan-α-glucosaminide N-acetyltransferase (HGSNAT). Mutations of HGSNAT cause HS accumulation and consequently mucopolysaccharidosis IIIC, a devastating lysosomal storage disease characterized by progressive neurological deterioration and early death where no treatment is available. HGSNAT catalyzes a unique transmembrane acetylation reaction where the acetyl group of cytosolic acetyl-CoA is transported across the lysosomal membrane and attached to HS in one reaction. However, the reaction mechanism remains elusive. Here we report six cryo-EM structures of HGSNAT along the reaction pathway. These structures reveal a dimer arrangement and a unique structural fold, which enables the elucidation of the reaction mechanism. We find that a central pore within each monomer traverses the membrane and controls access of cytosolic acetyl-CoA to the active site at its luminal mouth where glucosamine binds. A histidine-aspartic acid catalytic dyad catalyzes the transfer reaction via a ternary complex mechanism. Furthermore, the structures allow the mapping of disease-causing variants and reveal their potential impact on the function, thus creating a framework to guide structure-based drug discovery efforts. | |||||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8vkj.cif.gz | 224.8 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8vkj.ent.gz | 177.3 KB | Display | PDB format |
PDBx/mmJSON format | 8vkj.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8vkj_validation.pdf.gz | 1.5 MB | Display | wwPDB validaton report |
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Full document | 8vkj_full_validation.pdf.gz | 1.5 MB | Display | |
Data in XML | 8vkj_validation.xml.gz | 53.4 KB | Display | |
Data in CIF | 8vkj_validation.cif.gz | 76.7 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/vk/8vkj ftp://data.pdbj.org/pub/pdb/validation_reports/vk/8vkj | HTTPS FTP |
-Related structure data
Related structure data | 43319MC 8vlgC 8vliC 8vluC 8vlvC 8vlyC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 73365.039 Da / Num. of mol.: 2 / Mutation: Isoform 2 with N-terminal truncation Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: HGSNAT, TMEM76 / Production host: Homo sapiens (human) References: UniProt: Q68CP4, heparan-alpha-glucosaminide N-acetyltransferase #2: Polysaccharide | 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose | Source method: isolated from a genetically manipulated source #3: Sugar | ChemComp-NAG / #4: Chemical | Has ligand of interest | Y | Has protein modification | Y | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: Purified human HGSNAT / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Molecular weight | Value: 0.073 MDa / Experimental value: NO |
Source (natural) | Organism: Homo sapiens (human) |
Source (recombinant) | Organism: Homo sapiens (human) |
Buffer solution | pH: 7.5 |
Specimen | Conc.: 3.1 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
-Electron microscopy imaging
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 22000 nm / Nominal defocus min: 10000 nm |
Image recording | Electron dose: 1 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
-Processing
EM software | Name: PHENIX / Version: 1.20.1_4487: / Category: model refinement | ||||||||||||||||||||||||
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
3D reconstruction | Resolution: 2.92 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 169006 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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