1UJW

Structure of the complex between BtuB and Colicin E3 Receptor binding domain

Summary for 1UJW

• Entry DOI: 10.2210/pdb1ujw/pdb
• Related: 1JCH 1NQE
• Descriptor: Vitamin B12 receptor, Colicin E3, 2-amino-2-deoxy-1-O-phosphono-alpha-D-glucopyranose, ... (8 entities in total)
• Functional Keywords: beta-barrel, coiled-coil, transport protein-hydrolase complex, transport protein/hydrolase
• Biological source: Escherichia coli; More
• Total number of polymer chains: 2
• Total formula weight: 84972.55

Authors

Kurisu, G.,Zakharov, S.D.,Zhalnina, M.V.,Bano, S.,Eroukova, V.Y.,Rokitskaya, T.I.,Antonenko, Y.N.,Wiener, M.C.,Cramer, W.A. (deposition date: 2003-08-12, release date: 2003-11-25, Last modification date: 2023-10-25)

Primary citation

Kurisu, G.,Zakharov, S.D.,Zhalnina, M.V.,Bano, S.,Eroukova, V.Y.,Rokitskaya, T.I.,Antonenko, Y.N.,Wiener, M.C.,Cramer, W.A.
The structure of BtuB with bound colicin E3 R-domain implies a translocon
NAT.STRUCT.BIOL., 10:948-954, 2003

PubMed Abstract: Cellular import of colicin E3 is initiated by the Escherichia coli outer membrane cobalamin transporter, BtuB. The 135-residue 100-A coiled-coil receptor-binding domain (R135) of colicin E3 forms a 1:1 complex with BtuB whose structure at a resolution of 2.75 A is reported. Binding of R135 to the BtuB extracellular surface (DeltaG(o) = -12 kcal mol(-1)) is mediated by 27 residues of R135 near the coiled-coil apex. Formation of the R135-BtuB complex results in unfolding of R135 N- and C-terminal ends, inferred to be important for unfolding of the colicin T-domain. Small conformational changes occur in the BtuB cork and barrel domains but are insufficient to form a translocation channel. The absence of a channel and the peripheral binding of R135 imply that BtuB serves to bind the colicin, and that the coiled-coil delivers the colicin to a neighboring outer membrane protein for translocation, thus forming a colicin translocon. The translocator was concluded to be OmpF from the occlusion of OmpF channels by colicin E3.

PubMed: 14528295
DOI: 10.1038/nsb997

Experimental method

X-RAY DIFFRACTION (2.75 Å)