4K7K

Crystal structures of CusC review conformational changes accompanying folding and transmembrane channel formation

Summary for 4K7K

• Entry DOI: 10.2210/pdb4k7k/pdb
• Descriptor: Cation efflux system protein CusC (2 entities in total)
• Functional Keywords: beta barrel, membrane protein
• Biological source: Escherichia coli
• Cellular location: Cell outer membrane; Multi-pass membrane protein: P77211
• Total number of polymer chains: 2
• Total formula weight: 98783.95

Authors

Su, C.-C.,Lei, H.-T. (deposition date: 2013-04-17, release date: 2013-10-16, Last modification date: 2024-02-28)

Primary citation

Lei, H.T.,Bolla, J.R.,Bishop, N.R.,Su, C.C.,Yu, E.W.
Crystal Structures of CusC Review Conformational Changes Accompanying Folding and Transmembrane Channel Formation.
J.Mol.Biol., 426:403-411, 2014

PubMed Abstract: Gram-negative bacteria, such as Escherichia coli, frequently utilize tripartite efflux complexes in the RND (resistance-nodulation-cell division) family to expel diverse toxic compounds from the cell. These complexes span both the inner and outer membranes of the bacterium via an α-helical, inner membrane transporter; a periplasmic membrane fusion protein; and a β-barrel, outer membrane channel. One such efflux system, CusCBA, is responsible for extruding biocidal Cu(I) and Ag(I) ions. To remove these toxic ions, the CusC outer membrane channel must form a β-barrel structural domain, which creates a pore and spans the entire outer membrane. We here report the crystal structures of wild-type CusC, as well as two CusC mutants, suggesting that the first N-terminal cysteine residue plays an important role in protein-membrane interactions and is critical for the insertion of this channel protein into the outer membrane. These structures provide insight into the mechanisms on CusC folding and transmembrane channel formation. It is found that the interactions between CusC and membrane may be crucial for controlling the opening and closing of this β-barrel, outer membrane channel.

PubMed: 24099674
DOI: 10.1016/j.jmb.2013.09.042

Experimental method

X-RAY DIFFRACTION (2.53 Å)