2YV9

Crystal structure of the CLIC homologue EXC-4 from c. elegans

Summary for 2YV9

• Entry DOI: 10.2210/pdb2yv9/pdb
• Related: 1K0M 2AHE 2YU7
• Descriptor: Chloride intracellular channel exc-4, CALCIUM ION (3 entities in total)
• Functional Keywords: chloride ion channel, clic, gst fold, exc-4, metal transport
• Biological source: Caenorhabditis elegans
• Cellular location: Cytoplasm: Q8WQA4
• Total number of polymer chains: 2
• Total formula weight: 67721.46

Authors

Harrop, S.J.,Littler, D.R.,Curmi, P.M.G. (deposition date: 2007-04-10, release date: 2008-02-19, Last modification date: 2023-10-25)

Primary citation

Littler, D.R.,Harrop, S.J.,Brown, L.J.,Pankhurst, G.J.,Mynott, A.V.,Luciani, P.,Mandyam, R.A.,Mazzanti, M.,Tanda, S.,Berryman, M.A.,Breit, S.N.,Curmi, P.M.G.
Comparison of vertebrate and invertebrate CLIC proteins: The crystal structures of Caenorhabditis elegans EXC-4 and Drosophila melanogaster DmCLIC
Proteins, 71:364-378, 2007

PubMed Abstract: The crystal structures of two CLIC family members DmCLIC and EXC-4 from the invertebrates Drosophila melanogaster and Caenorhabditis elegans, respectively, have been determined. The proteins adopt a glutathione S-transferase (GST) fold. The structures are highly homologous to each other and more closely related to the known structures of the human CLIC1 and CLIC4 than to GSTs. The invertebrate CLICs show several unique features including an elongated C-terminal extension and a divalent metal binding site. The latter appears to alter the ancestral glutathione binding site, and thus, the invertebrate CLICs are unlikely to bind glutathione in the same manner as the GST proteins. Purified recombinant DmCLIC and EXC-4 both bind to lipid bilayers and can form ion channels in artificial lipid bilayers, albeit at low pH. EXC-4 differs from other CLIC proteins in that the conserved redox-active cysteine at the N-terminus of helix 1 is replaced by an aspartic acid residue. Other key distinguishing features of EXC-4 include the fact that it binds to artificial bilayers at neutral pH and this binding is not sensitive to oxidation. These differences with other CLIC family members are likely to be due to the substitution of the conserved cysteine by aspartic acid.

PubMed: 17985355
DOI: 10.1002/prot.21704

Experimental method

X-RAY DIFFRACTION (1.6 Å)