5tqq

Cryo-electron microscopy structure of a bovine CLC-K chloride channel, main (class 1) conformationCryo-electron microscopy structure of a bovine CLC-K chloride channel, main (class 1) conformation

5tqq, resolution 3.76Å Show:Asymmetric Unit Biological Assembly Structural highlights 5tqq is a 6 chain structure with sequence from Bos taurus and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.76Å Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function E1B792_BOVIN Publication Abstract from PubMed CLC proteins transport chloride (Cl-) ions across cellular membranes to regulate muscle excitability, electrolyte movement across epithelia, and acidification of intracellular organelles. Some CLC proteins are channels that conduct Cl- ions passively, whereas others are secondary active transporters that exchange two Cl- ions for one H+. The structural basis underlying these distinctive transport mechanisms is puzzling because CLC channels and transporters are expected to share the same architecture on the basis of sequence homology. Here we determined the structure of a bovine CLC channel (CLC-K) using cryo-electron microscopy. A conserved loop in the Cl- transport pathway shows a structure markedly different from that of CLC transporters. Consequently, the cytosolic constriction for Cl- passage is widened in CLC-K such that the kinetic barrier previously postulated for Cl-/H+ transporter function would be reduced. Thus, reduction of a kinetic barrier in CLC channels enables fast flow of Cl- down its electrochemical gradient. Structure of a CLC chloride ion channel by cryo-electron microscopy.,Park E, Campbell EB, MacKinnon R Nature. 2016 Dec 21. doi: 10.1038/nature20812. PMID:28002411 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ion channels 3D structures Monoclonal Antibodies 3D structures