9Z1M | pdb_00009z1m

Cryo-EM structure of KP.3 spike in complex with Nb9B


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.06 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 9Z1M

This is version 1.1 of the entry. See complete history

Literature

Update and reuse: Structure-guided nanobody evolution against SARS-CoV-2 escape.

Bu, F.Saxena, D.Turner-Hubbard, H.Delaney, A.Batra, L.Fricke, C.Moye, S.Verma, A.Perlman, S.Bhandari, J.Liu, B.Ye, G.Zheng, J.Li, F.

(2026) PLoS Pathog 22: e1014223-e1014223

  • DOI: https://doi.org/10.1371/journal.ppat.1014223
  • Primary Citation Related Structures: 
    9Z1M, 9Z1N

  • PubMed Abstract: 

    SARS-CoV-2 continues to accumulate spike mutations that erode the efficacy of antibody therapeutics. The Q493E mutation in the spike RBD, present in recent Omicron subvariants, enables escape from many antibodies and nanobodies, including our Nanosota-9A nanobody, which neutralizes Omicron JN.1 (Q493) but not KP.3 (E493). To address this, we applied a structure-guided in vitro evolution strategy to engineer Nanosota-9A, generating Nanosota-9B, which binds the KP.3 RBD with high affinity but shows reduced binding to JN.1 RBD. To regain breadth, we engineered a bispecific nanobody combining Nanosota-9A and -9B, which effectively neutralizes both JN.1 and KP.3 in infection assays. Our results provide proof of concept for an "update and reuse" strategy: applying structure-guided engineering to update and reuse validated nanobodies to overcome variant escape. This strategy offers a practical path to maintain therapeutic coverage as the virus evolves, supporting more efficient use of research resources and faster responses to emerging variants.


  • Organizational Affiliation
    • Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America.

Macromolecule Content 

  • Total Structure Weight: 469.4 kDa 
  • Atom Count: 28,750 
  • Modeled Residue Count: 3,633 
  • Deposited Residue Count: 4,179 
  • Unique protein chains: 2

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Nanosota-9BA [auth D],
B [auth E],
C [auth F]
150Vicugna pacosMutation(s): 0 
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
KP.3 spikeD [auth B],
E [auth C],
F [auth A]
1,243Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
UniProt
Find proteins for A0A6V7ALX9 (Severe acute respiratory syndrome coronavirus 2)
Explore A0A6V7ALX9 
Go to UniProtKB:  A0A6V7ALX9
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A6V7ALX9
Glycosylation
Glycosylation Sites: 4
Sequence Annotations
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Reference Sequence

Oligosaccharides

Help  
Entity ID: 3
MoleculeChains Length2D Diagram GlycosylationD Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
G, H, I, J, K
G, H, I, J, K, L, M, N, O, P, Q
2N-Glycosylation
Glycosylation Resources
GlyTouCan: G42666HT
GlyCosmos: G42666HT
GlyGen: G42666HT

Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.06 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX1.21.1_5286
RECONSTRUCTIONcryoSPARC

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)United StatesU19 AI171954

Revision History  (Full details and data files)

  • Version 1.0: 2026-05-13
    Type: Initial release
  • Version 1.1: 2026-06-24
    Changes: Data collection, Database references