3GZC

Structure of human selenocysteine lyase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Biochemical discrimination between selenium and sulfur 1: a single residue provides selenium specificity to human selenocysteine lyase.

Collins, R.Johansson, A.L.Karlberg, T.Markova, N.van den Berg, S.Olesen, K.Hammarstrom, M.Flores, A.Schuler, H.Schiavone, L.H.Brzezinski, P.Arner, E.S.Hogbom, M.

(2012) Plos One 7: e30581-e30581

  • DOI: 10.1371/journal.pone.0030581
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • 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 ( ...

    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.


    Organizational Affiliation

    Structural Genomics Consortium, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Selenocysteine lyase
A, B
440Homo sapiensMutation(s): 0 
Gene Names: SCLY (SCL)
EC: 4.4.1.16
Find proteins for Q96I15 (Homo sapiens)
Go to Gene View: SCLY
Go to UniProtKB:  Q96I15
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLR
Query on PLR

Download SDF File 
Download CCD File 
A, B
(5-HYDROXY-4,6-DIMETHYLPYRIDIN-3-YL)METHYL DIHYDROGEN PHOSPHATE
4'-DEOXYPYRIDOXINE PHOSPHATE
C8 H12 N O5 P
RBCOYOYDYNXAFA-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.179 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 59.218α = 90.00
b = 85.813β = 90.00
c = 188.578γ = 90.00
Software Package:
Software NamePurpose
XSCALEdata scaling
MxCuBEdata collection
XDSdata reduction
MOLREPphasing
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Revision History 

  • Version 1.0: 2009-04-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.2: 2012-06-13
    Type: Database references