4RB4

Crystal structure of dodecameric iron-containing heptosyltransferase TibC in complex with ADP-D-beta-D-heptose at 3.9 angstrom resolution

Summary for 4RB4

• Entry DOI: 10.2210/pdb4rb4/pdb
• Related: 4Q1Q 4RAP
• Descriptor: Glycosyltransferase tibC, FE (III) ION, [(2R,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxytetrahydrofuran-2-yl]methyl (2R,3R,4R,5R,6S)-6-[(1R)-1,2-dihydroxyethyl]-3,4,5-trihydroxytetrahydro-2H-pyran-2-yl dihydrogen diphosphate, ... (4 entities in total)
• Functional Keywords: gt-b fold, heptose transfer, tiba, adp-d-beta-d-heptose, transferase
• Biological source: Escherichia coli DEC13E
• Total number of polymer chains: 12
• Total formula weight: 564302.76

Authors

Yao, Q.,Lu, Q.,Shao, F. (deposition date: 2014-09-12, release date: 2014-11-05, Last modification date: 2023-11-08)

Primary citation

Yao, Q.,Lu, Q.,Wan, X.,Song, F.,Xu, Y.,Hu, M.,Zamyatina, A.,Liu, X.,Huang, N.,Zhu, P.,Shao, F.
A structural mechanism for bacterial autotransporter glycosylation by a dodecameric heptosyltransferase family
Elife, 3:-, 2014

PubMed Abstract: 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.

PubMed: 25310236
DOI: 10.7554/eLife.03714

Experimental method

X-RAY DIFFRACTION (3.88 Å)