Hsa Siglec and Unique domains in complex with Sialyl Lewis C

  • Classification: CELL ADHESION
  • Organism(s): Streptococcus gordonii str. Challis
  • Expression System: Escherichia coli
  • Mutation(s): No 

  • Deposited: 2020-11-03 Released: 2022-05-25 
  • Deposition Author(s): Stubbs, H.E., Iverson, T.M.
  • Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID), American Heart Association, National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

Experimental Data Snapshot

  • Resolution: 1.33 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.192 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Origins of glycan selectivity in streptococcal Siglec-like adhesins suggest mechanisms of receptor adaptation.

Bensing, B.A.Stubbs, H.E.Agarwal, R.Yamakawa, I.Luong, K.Solakyildirim, K.Yu, H.Hadadianpour, A.Castro, M.A.Fialkowski, K.P.Morrison, K.M.Wawrzak, Z.Chen, X.Lebrilla, C.B.Baudry, J.Smith, J.C.Sullam, P.M.Iverson, T.M.

(2022) Nat Commun 13: 2753-2753

  • DOI: https://doi.org/10.1038/s41467-022-30509-y
  • Primary Citation of Related Structures:  
    6EF7, 6EF9, 6EFA, 6EFB, 6EFC, 6EFD, 6EFF, 6EFI, 6X3K, 6X3Q, 7KMJ

  • PubMed Abstract: 

    Bacterial binding to host receptors underlies both commensalism and pathogenesis. Many streptococci adhere to protein-attached carbohydrates expressed on cell surfaces using Siglec-like binding regions (SLBRs). The precise glycan repertoire recognized may dictate whether the organism is a strict commensal versus a pathogen. However, it is currently not clear what drives receptor selectivity. Here, we use five representative SLBRs and identify regions of the receptor binding site that are hypervariable in sequence and structure. We show that these regions control the identity of the preferred carbohydrate ligand using chimeragenesis and single amino acid substitutions. We further evaluate how the identity of the preferred ligand affects the interaction with glycoprotein receptors in human saliva and plasma samples. As point mutations can change the preferred human receptor, these studies suggest how streptococci may adapt to changes in the environmental glycan repertoire.

  • Organizational Affiliation

    Division of Infectious Diseases, Veterans Affairs Medical Center, Department of Medicine, University of California, San Francisco, CA, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Streptococcal hemagglutinin234Streptococcus gordonii str. ChallisMutation(s): 0 
Gene Names: hsaSGO_0966
Find proteins for A8AWU7 (Streptococcus gordonii (strain Challis / ATCC 35105 / BCRC 15272 / CH1 / DL1 / V288))
Explore A8AWU7 
Go to UniProtKB:  A8AWU7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA8AWU7
Sequence Annotations
  • Reference Sequence


Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
N-acetyl-alpha-neuraminic acid-(2-3)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranoseB [auth K]3N/A
Glycosylation Resources
GlyTouCan:  G00065MO
GlyCosmos:  G00065MO
GlyGen:  G00065MO
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.635α = 90
b = 58.173β = 90
c = 75.973γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)--
American Heart Association--
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)--

Revision History  (Full details and data files)

  • Version 1.0: 2022-05-25
    Type: Initial release
  • Version 1.1: 2022-06-01
    Changes: Database references
  • Version 1.2: 2023-10-18
    Changes: Data collection, Refinement description