1cii
From Proteopedia
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| , resolution 3.0Å | |||||||
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| Gene: | CIA (Escherichia coli) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
COLICIN IA
Overview
The ion-channel forming colicins A, B, E1, Ia, Ib and N all kill bacterial cells selectively by co-opting bacterial active-transport pathways and forming voltage-gated ion conducting channels across the plasma membrane of the target bacterium. The crystal structure of colicin Ia reveals a molecule 210 A long with three distinct functional domains arranged along a backbone of two extraordinarily long alpha-helices. A central domain at the bend of the hairpin-like structure mediates specific recognition and binding to an outer-membrane receptor. A second domain mediates translocation across the outer membrane via the TonB transport pathway; the TonB-box recognition element of colicin Ia is on one side of three 80 A-long helices arranged as a helical sheet. A third domain is made up of 10 alpha-helices which form a voltage-activated and voltage-gated ion conducting channel across the plasma membrane of the target cell. The two 160 A-long alpha-helices that link the receptor-binding domain to the other domains enable the colicin Ia molecule to span the periplasmic space and contact both the outer and plasma membranes simultaneously during function.
About this Structure
1CII is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystal structure of colicin Ia., Wiener M, Freymann D, Ghosh P, Stroud RM, Nature. 1997 Jan 30;385(6615):461-4. PMID:9009197
Page seeded by OCA on Thu Mar 20 10:24:48 2008
