The molecular basis of regulation of bacterial capsule assembly by Wzc.
Nat Commun
; 12(1): 4349, 2021 07 16.
Article
in En
| MEDLINE
| ID: mdl-34272394
ABSTRACT
Bacterial extracellular polysaccharides (EPSs) play critical roles in virulence. Many bacteria assemble EPSs via a multi-protein "Wzx-Wzy" system, involving glycan polymerization at the outer face of the cytoplasmic/inner membrane. Gram-negative species couple polymerization with translocation across the periplasm and outer membrane and the master regulator of the system is the tyrosine autokinase, Wzc. This near atomic cryo-EM structure of dephosphorylated Wzc from E. coli shows an octameric assembly with a large central cavity formed by transmembrane helices. The tyrosine autokinase domain forms the cytoplasm region, while the periplasmic region contains small folded motifs and helical bundles. The helical bundles are essential for function, most likely through interaction with the outer membrane translocon, Wza. Autophosphorylation of the tyrosine-rich C-terminus of Wzc results in disassembly of the octamer into multiply phosphorylated monomers. We propose that the cycling between phosphorylated monomer and dephosphorylated octamer regulates glycan polymerization and translocation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polysaccharides, Bacterial
/
Protein-Tyrosine Kinases
/
Bacterial Capsules
/
Periplasm
/
Escherichia coli Proteins
/
Escherichia coli
/
Membrane Proteins
Language:
En
Journal:
Nat Commun
Journal subject:
BIOLOGIA
/
CIENCIA
Year:
2021
Document type:
Article
Affiliation country:
United kingdom