Download MendeleyA Coiled-Coil Domain Acts as a Molecular Ruler to Regulate O-Antigen Chain Length in Lipopolysaccharide.
Hagelueken, G., Clarke, B.R., Huang, H., Tuukkanen, A., Danciu, I., Svergun, D.I., Hussain, R., Liu, H., Whitfield, C., Naismith, J.H.(2015) Nat Struct Mol Biol 22: 50
- PubMed: 25504321
- DOI: https://doi.org/10.1038/nsmb.2935
- Primary Citation of Related Structures:
4UW0 - PubMed Abstract:
Long-chain bacterial polysaccharides have important roles in pathogenicity. In Escherichia coli O9a, a model for ABC transporter-dependent polysaccharide assembly, a large extracellular carbohydrate with a narrow size distribution is polymerized from monosaccharides by a complex of two proteins, WbdA (polymerase) and WbdD (terminating protein). Combining crystallography and small-angle X-ray scattering, we found that the C-terminal domain of WbdD contains an extended coiled-coil that physically separates WbdA from the catalytic domain of WbdD. The effects of insertions and deletions in the coiled-coil region were analyzed in vivo, revealing that polymer size is controlled by varying the length of the coiled-coil domain. Thus, the coiled-coil domain of WbdD functions as a molecular ruler that, along with WbdA:WbdD stoichiometry, controls the chain length of a model bacterial polysaccharide.
Organizational Affiliation:
Biomedical Sciences Research Complex, University of St Andrews, St Andrews, Fife, KY16 9ST, UK.
