3A9Z

Crystal structure of ras selenocysteine lyase in complex with selenopropionate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Reaction mechanism and molecular basis for selenium/sulfur discrimination of selenocysteine lyase.

Omi, R.Kurokawa, S.Mihara, H.Hayashi, H.Goto, M.Miyahara, I.Kurihara, T.Hirotsu, K.Esaki, N.

(2010) J Biol Chem 285: 12133-12139

  • DOI: 10.1074/jbc.M109.084475
  • Primary Citation of Related Structures:  
    3A9X, 3A9Y, 3A9Z

  • PubMed Abstract: 
  • Selenocysteine lyase (SCL) catalyzes the pyridoxal 5'-phosphate-dependent removal of selenium from l-selenocysteine to yield l-alanine. The enzyme is proposed to function in the recycling of the micronutrient selenium from degraded selenoproteins containing selenocysteine residue as an essential component ...

    Selenocysteine lyase (SCL) catalyzes the pyridoxal 5'-phosphate-dependent removal of selenium from l-selenocysteine to yield l-alanine. The enzyme is proposed to function in the recycling of the micronutrient selenium from degraded selenoproteins containing selenocysteine residue as an essential component. The enzyme exhibits strict substrate specificity toward l-selenocysteine and no activity to its cognate l-cysteine. However, it remains unclear how the enzyme distinguishes between selenocysteine and cysteine. Here, we present mechanistic studies of selenocysteine lyase from rat. ESI-MS analysis of wild-type and C375A mutant SCL revealed that the catalytic reaction proceeds via the formation of an enzyme-bound selenopersulfide intermediate on the catalytically essential Cys-375 residue. UV-visible spectrum analysis and the crystal structure of SCL complexed with l-cysteine demonstrated that the enzyme reversibly forms a nonproductive adduct with l-cysteine. Cys-375 on the flexible loop directed l-selenocysteine, but not l-cysteine, to the correct position and orientation in the active site to initiate the catalytic reaction. These findings provide, for the first time, the basis for understanding how trace amounts of a selenium-containing substrate is distinguished from excessive amounts of its cognate sulfur-containing compound in a biological system.


    Organizational Affiliation

    Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Selenocysteine lyaseA, B432Rattus norvegicusMutation(s): 0 
Gene Names: Scly
EC: 4.4.1.16
Find proteins for Q68FT9 (Rattus norvegicus)
Explore Q68FT9 
Go to UniProtKB:  Q68FT9
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLP
Query on PLP

Download Ideal Coordinates CCD File 
C [auth A], G [auth B]PYRIDOXAL-5'-PHOSPHATE
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
SLP
Query on SLP

Download Ideal Coordinates CCD File 
D [auth A], H [auth B]3-selanylpropanoic acid
C3 H6 O2 Se
DGRAMMLRUJGIJS-UHFFFAOYSA-N
 Ligand Interaction
PO4
Query on PO4

Download Ideal Coordinates CCD File 
E [auth A], F [auth A]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.416α = 90
b = 101.206β = 90
c = 197.356γ = 90
Software Package:
Software NamePurpose
CNSrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2009-11-09 
  • Released Date: 2010-03-16 
  • Deposition Author(s): Omi, R., Hirotsu, K.

Revision History  (Full details and data files)

  • Version 1.0: 2010-03-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2013-10-30
    Changes: Database references