9IUF

Cryo-EM structure of the type IVb pilus from enterotoxigenic Escherichia coli

Summary for 9IUF

• Entry DOI: 10.2210/pdb9iuf/pdb
• EMDB information: 60902
• Descriptor: CFA/III pilin (2 entities in total)
• Functional Keywords: type iv pili, colonization factor, cell adhesion
• Biological source: Escherichia coli
• Total number of polymer chains: 18
• Total formula weight: 389167.52

Authors

Kawahara, K.,Oki, H.,Nakamura, S. (deposition date: 2024-07-21, release date: 2025-05-28, Last modification date: 2025-06-25)

Primary citation

Kawahara, K.,Oki, H.,Iimori, M.,Muramoto, R.,Imai, T.,Gerle, C.,Shigematsu, H.,Matsuda, S.,Iida, T.,Nakamura, S.
High-resolution cryo-EM analysis visualizes hydrated type I and IV pilus structures from enterotoxigenic Escherichia coli.
Structure, 33:1040-, 2025

PubMed Abstract: Pathogenic bacteria utilize a variety of pilus filaments to colonize intestinal epithelia, including those synthesized by the chaperone-usher or type IV pilus assembly pathway. Despite the importance of these filaments as potential drug and vaccine targets, their large size and dynamic nature make high-resolution structure determination challenging. Here, we used cryo-electron microscopy (cryo-EM) and whole-genome sequencing to determine the structures of type I and IV pili expressed in enterotoxigenic Escherichia coli. Well-defined cryo-EM maps at resolutions of 2.2 and 1.8 Å for type I and IV pilus, respectively, facilitated the de novo structural modeling for these filaments, revealing side-chain structures in detail. We resolved thousands of hydrated water molecules around and within the inner core of the filaments, which stabilize the otherwise metastable quaternary subunit assembly. The high-resolution structures offer novel insights into subunit-subunit interactions, and provide important clues to understand pilus assembly, stability, and flexibility.

PubMed: 40220752
DOI: 10.1016/j.str.2025.03.010

Experimental method

ELECTRON MICROSCOPY (1.78 Å)