9R62

CPS co-polymerase Wzc_C1

Summary for 9R62

• Entry DOI: 10.2210/pdb9r62/pdb
• EMDB information: 53600
• Descriptor: Tyrosine-protein kinase wzc, ADENOSINE-5'-DIPHOSPHATE, MAGNESIUM ION (3 entities in total)
• Functional Keywords: capsular polysaccharide co-polymerase, transport protein
• Biological source: Escherichia coli K-12
• Total number of polymer chains: 8
• Total formula weight: 656068.74

Authors

Yuan, B.,Heinz, D.W. (deposition date: 2025-05-11, release date: 2026-03-04, Last modification date: 2026-07-29)

Primary citation

Yuan, B.,Sieben, C.,Raj, P.,Rietschel, T.,Hennell James, R.,Gatzemeier, A.,Jansch, L.,Marlovits, T.C.,Heinz, D.W.
Molecular insights into the capsular polysaccharide transporter Wza-Wzc complex.
Nat Commun, 17:1436-1436, 2026

PubMed Abstract: Capsular polysaccharides (CPS) are key virulence determinants, constituting the protective capsule that surrounds bacterial pathogens. Here, we present the complete cryo-EM structure of Gram-negative bacterial CPS secretion machinery formed by the E. coli K12 Wza-Wzc complex. The structure reveals an elongated, continuous channel spanning the entire envelope that facilitates CPS secretion. Multiple structural snapshots of the ADP-bound Wza-Wzc complex capture intermediate conformations of the double membrane assembly, highlighting its remarkable intrinsic dynamics. In-depth analysis of the isolated Wza translocon and Wzc co-polymerase, reveals mechanistic details of both complex formation and CPS transport. We further uncover the jellyroll domain of Wzc as a CPS-binding module, likely guiding CPS repeat units into a proposed Wzc-Wzy polymerization platform. Collectively, this work provides structural and functional insights into CPS synthesis and transport, advancing our understanding of bacterial capsule formation and virulence mechanisms.

PubMed: 41644548
DOI: 10.1038/s41467-026-69136-2

Experimental method

ELECTRON MICROSCOPY (3.4 Å)