A structural mechanism for bacterial autotransporter glycosylation by a dodecameric heptosyltransferase family.Yao, Q., Lu, Q., Wan, X., Song, F., Xu, Y., Hu, M., Zamyatina, A., Liu, X., Huang, N., Zhu, P., Shao, F.
(2014) Elife 3
- PubMed: 25310236
- DOI: 10.7554/eLife.03714
- Structures With Same Primary Citation
- PubMed Abstract:
- An iron-containing dodecameric heptosyltransferase family modifies bacterial autotransporters in pathogenesis.
Lu, Q., Yao, Q., Xu, Y., Li, L., Li, S., Liu, Y., Gao, W., Niu, M., Sharon, M., Ben-Nissan, G., Zamyatina, A., Liu, X., Chen, S., Shao, F.
(2014) Cell Host Microbe 16: 351
A large group of bacterial virulence autotransporters including AIDA-I from diffusely adhering E. coli (DAEC) and TibA from enterotoxigenic E. coli (ETEC) require hyperglycosylation for functioning. Here we demonstrate that TibC from ETEC harbors a h ...
A large group of bacterial virulence autotransporters including AIDA-I from diffusely adhering E. coli (DAEC) and TibA from enterotoxigenic E. coli (ETEC) require hyperglycosylation for functioning. Here we demonstrate that TibC from ETEC harbors a heptosyltransferase activity on TibA and AIDA-I, defining a large family of bacterial autotransporter heptosyltransferases (BAHTs). The crystal structure of TibC reveals a characteristic ring-shape dodecamer. The protomer features an N-terminal β-barrel, a catalytic domain, a β-hairpin thumb, and a unique iron-finger motif. The iron-finger motif contributes to back-to-back dimerization; six dimers form the ring through β-hairpin thumb-mediated hand-in-hand contact. The structure of ADP-D-glycero-β-D-manno-heptose (ADP-D,D-heptose)-bound TibC reveals a sugar transfer mechanism and also the ligand stereoselectivity determinant. Electron-cryomicroscopy analyses uncover a TibC-TibA dodecamer/hexamer assembly with two enzyme molecules binding to one TibA substrate. The complex structure also highlights a high efficient hyperglycosylation of six autotransporter substrates simultaneously by the dodecamer enzyme complex.
Dr Feng Shao's Laboratory, National Institute of Biological Sciences, Beijing, China.