7SP9 | pdb_00007sp9

Chlorella virus Hyaluronan Synthase in the GlcNAc-primed channel-closed state

• PDB DOI: https://doi.org/10.2210/pdb7SP9/pdb
• EM Map EMD-25369: EMDB EMDataResource

• Classification: MEMBRANE PROTEIN
• Organism(s): Lama glama, Paramecium bursaria Chlorella virus CZ-2
• Expression System: Escherichia coli K-12, Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2021-11-02 Released: 2022-04-06 
• Deposition Author(s): Maloney, F.P., Kuklewicz, J., Zimmer, J.
• Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Structure, substrate recognition and initiation of hyaluronan synthase.

Maloney, F.P., Kuklewicz, J., Corey, R.A., Bi, Y., Ho, R., Mateusiak, L., Pardon, E., Steyaert, J., Stansfeld, P.J., Zimmer, J.

(2022) Nature 604: 195-201

• PubMed: 35355017 
• DOI: https://doi.org/10.1038/s41586-022-04534-2
• Primary Citation Related Structures: 
  7SP6, 7SP7, 7SP8, 7SP9, 7SPA


• PubMed Abstract: 
  

  Hyaluronan is an acidic heteropolysaccharide comprising alternating N-acetylglucosamine and glucuronic acid sugars that is ubiquitously expressed in the vertebrate extracellular matrix ¹ . The high-molecular-mass polymer modulates essential physiological processes in health and disease, including cell differentiation, tissue homeostasis and angiogenesis ² . Hyaluronan is synthesized by a membrane-embedded processive glycosyltransferase, hyaluronan synthase (HAS), which catalyses the synthesis and membrane translocation of hyaluronan from uridine diphosphate-activated precursors ^3,4 . Here we describe five cryo-electron microscopy structures of a viral HAS homologue at different states during substrate binding and initiation of polymer synthesis. Combined with biochemical analyses and molecular dynamics simulations, our data reveal how HAS selects its substrates, hydrolyses the first substrate to prime the synthesis reaction, opens a hyaluronan-conducting transmembrane channel, ensures alternating substrate polymerization and coordinates hyaluronan inside its transmembrane pore. Our research suggests a detailed model for the formation of an acidic extracellular heteropolysaccharide and provides insights into the biosynthesis of one of the most abundant and essential glycosaminoglycans in the human body.

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Organizational Affiliation: 
• Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, USA.
Department of Biochemistry, University of Oxford, Oxford, UK.
Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.
CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.
Laboratory for In Vivo Cellular and Molecular Imaging, ICMI-BEFY, Vrije Universiteit Brussel, Brussels, Belgium.
VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium.
Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium.
School of Life Sciences and Department of Chemistry, University of Warwick, Coventry, UK.
Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA, USA. [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 3-mer - A1B1C1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 3-mer - A2B1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: assay for oligomerization

Macromolecule Content 

• Total Structure Weight: 96.09 kDa 
• Atom Count: 5,966 
• Modeled Residue Count: 737 
• Deposited Residue Count: 841 
• Unique protein chains: 3

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Nanobody 872	A [auth B]	134	Lama glama	Mutation(s): 0

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Nanobody 881	B [auth C]	137	Lama glama	Mutation(s): 0

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
Hyaluronan synthase	C [auth A]	570	Paramecium bursaria Chlorella virus CZ-2	Mutation(s): 1  Gene Names: CZ-2_118R, PBCVCZ2_118R
UniProt
Find proteins for A0ACD6B8N5 (Paramecium bursaria Chlorella virus CZ-2) Explore A0ACD6B8N5  Go to UniProtKB:  A0ACD6B8N5

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
Y01	E [auth A]	CHOLESTEROL HEMISUCCINATE C31 H50 O4 WLNARFZDISHUGS-MIXBDBMTSA-N
NAG (Subject of Investigation/LOI)	D [auth A]	2-acetamido-2-deoxy-beta-D-glucopyranose C8 H15 N O6 OVRNDRQMDRJTHS-FMDGEEDCSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	cryoSPARC	3.1

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2022-04-06 
Deposition Author(s): Maloney, F.P., Kuklewicz, J., Zimmer, J.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)	United States	R21AI148853

Revision History  

• Version 1.0: 2022-04-06
  Type: Initial release
  
• Version 1.1: 2022-04-13
  Changes: Database references
• Version 1.2: 2022-04-20
  Changes: Database references
• Version 1.3: 2024-11-20
  Changes: Data collection, Structure summary