7SP9 image
Entry Detail
PDB ID:
7SP9
EMDB ID:
Title:
Chlorella virus Hyaluronan Synthase in the GlcNAc-primed channel-closed state
Biological Source:
PDB Version:
Deposition Date:
2021-11-02
Release Date:
2022-04-06
Method Details:
Experimental Method:
Resolution:
2.90 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Hyaluronan synthase
Mutations:D302N
Chain IDs:C (auth: A)
Chain Length:570
Number of Molecules:1
Biological Source:Paramecium bursaria Chlorella virus CZ-2
Polymer Type:polypeptide(L)
Description:Nanobody 872
Chain IDs:A (auth: B)
Chain Length:134
Number of Molecules:1
Biological Source:Lama glama
Polymer Type:polypeptide(L)
Description:Nanobody 881
Chain IDs:B (auth: C)
Chain Length:137
Number of Molecules:1
Biological Source:Lama glama
Primary Citation
Structure, substrate recognition and initiation of hyaluronan synthase.
Nature 604 195 201 (2022)
PMID: 35355017 DOI: 10.1038/s41586-022-04534-2

Abstact

Hyaluronan is an acidic heteropolysaccharide comprising alternating N-acetylglucosamine and glucuronic acid sugars that is ubiquitously expressed in the vertebrate extracellular matrix1. The high-molecular-mass polymer modulates essential physiological processes in health and disease, including cell differentiation, tissue homeostasis and angiogenesis2. 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 precursors3,4. 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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Primary Citation of related structures