3gzc

Structure of human selenocysteine lyaseStructure of human selenocysteine lyase

Structural highlights 3gzc is a 2 chain structure with sequence from Homo sapiens. This structure supersedes the now removed PDB entry 2hdy. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Gene: SCL, SCLY (Homo sapiens) Activity: Selenocysteine lyase, with EC number 4.4.1.16 Resources: FirstGlance, OCA, RCSB, PDBsum Function [SCLY_HUMAN] Catalyzes the decomposition of L-selenocysteine to L-alanine and elemental selenium (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Selenium and sulfur are two closely related basic elements utilized in nature for a vast array of biochemical reactions. While toxic at higher concentrations, selenium is an essential trace element incorporated into selenoproteins as selenocysteine (Sec), the selenium analogue of cysteine (Cys). Sec lyases (SCLs) and Cys desulfurases (CDs) catalyze the removal of selenium or sulfur from Sec or Cys and generally act on both substrates. In contrast, human SCL (hSCL) is specific for Sec although the only difference between Sec and Cys is the identity of a single atom. The chemical basis of this selenium-over-sulfur discrimination is not understood. Here we describe the X-ray crystal structure of hSCL and identify Asp146 as the key residue that provides the Sec specificity. A D146K variant resulted in loss of Sec specificity and appearance of CD activity. A dynamic active site segment also provides the structural prerequisites for direct product delivery of selenide produced by Sec cleavage, thus avoiding release of reactive selenide species into the cell. We thus here define a molecular determinant for enzymatic specificity discrimination between a single selenium versus sulfur atom, elements with very similar chemical properties. Our findings thus provide molecular insights into a key level of control in human selenium and selenoprotein turnover and metabolism. Biochemical discrimination between selenium and sulfur 1: a single residue provides selenium specificity to human selenocysteine lyase.,Collins R, Johansson AL, Karlberg T, Markova N, van den Berg S, Olesen K, Hammarstrom M, Flores A, Schuler H, Schiavone LH, Brzezinski P, Arner ES, Hogbom M PLoS One. 2012;7(1):e30581. Epub 2012 Jan 25. PMID:22295093 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 3gzc, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image