Covalently constrained ‘Di-Gembodies’ enable parallel structure solutions by cryo-EM

Yi G., Mamalis D., Ye M., Carrique L., Fairhead M., Li H., Duerr KL., Zhang P., Sauer DB., von Delft F., Davis BG., Gilbert RJC.

Abstract Whilst cryo-electron microscopy(cryo-EM) has become a routine methodology in structural biology, obtaining high-resolution cryo-EM structures of small proteins (<100 kDa) and increasing overall throughput remain challenging. One approach to augment protein size and improve particle alignment involves the use of binding proteins or protein-based scaffolds. However, a given imaging scaffold or linking module may prove inadequate for structure solution and availability of such scaffolds remains limited. Here, we describe a strategy that exploits covalent dimerization of nanobodies to trap an engineered, predisposed nanobody-to-nanobody interface, giving Di-Gembodies as modular constructs created in homomeric and heteromeric forms. By exploiting side-chain-to-side-chain assembly, they can simultaneously display two copies of the same or two distinct proteins through a subunit interface that provides sufficient constraint required for cryo-EM structure determination. We validate this method with multiple soluble and membrane structural targets, down to 14 kDa, demonstrating a flexible and scalable platform for expanded protein structure determination.

DOI

10.1038/s41589-025-01972-7

Type

Journal article

Publisher

Springer Science and Business Media LLC

Publication Date

2026-01-01T00:00:00+00:00

Volume

22

Pages

69 - 76

Total pages

7

Permalink More information Close