2PI6

Crystal structure of the sheep signalling glycoprotein (SPS-40) complex with 2-methyl-2-4-pentanediol at 1.65A resolution reveals specific binding characteristics of SPS-40


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.167 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Tryptophan as a three-way switch in regulating the function of the secretory signalling glycoprotein (SPS-40) from mammary glands: structure of SPS-40 complexed with 2-methylpentane-2,4-diol at 1.6 A resolution.

Sharma, P.Singh, N.Sinha, M.Sharma, S.Perbandt, M.Betzel, C.Kaur, P.Srinivasan, A.Singh, T.P.

(2009) Acta Crystallogr.,Sect.D 65: 375-378

  • DOI: 10.1107/S0907444909002327

  • PubMed Abstract: 
  • The 40 kDa secretory signalling glycoprotein (SPS-40) is the first example with Trp78 in three functional orientations: (i) a resting state with a pinched conformation, (ii) a stacked conformation when bound to hexasaccharide and (iii) an obstructive ...

    The 40 kDa secretory signalling glycoprotein (SPS-40) is the first example with Trp78 in three functional orientations: (i) a resting state with a pinched conformation, (ii) a stacked conformation when bound to hexasaccharide and (iii) an obstructive conformation when inhibited by 2-methylpentane-2,4-diol (MPD). Trp78 is present in the core of the sugar-binding groove. The hexasaccharide N-acetylglucosamine (GlcNAc(6)) has been shown to bind to SPS-40. As a result of this, the conformation of Trp78 alters from the native pinched conformation (chi(1) = -65.5 degrees , chi(2,1) = -78.8 degrees , chi(2,2) = 97.5 degrees ) to the stacked conformation (chi(1) = -170.0 degrees , chi(2,1) = -114.3 degrees , chi(2,2) = 61.6 degrees ). Further binding experiments showed that saccharide binding does not occur in the presence of 20% MPD. The crystal structure determination of the complex of SPS-40 with MPD revealed the presence of two MPD molecules in the sugar-binding groove. The very tightly bound MPD molecules at subsites -2 and -1 induced an unexpected and a rarely observed conformation of Trp78 (chi(1) = 55.9 degrees , chi(2,1) = 90.2 degrees , chi(2,2) = -88.9 degrees ) which is termed an obstructive conformation. The binding of MPD molecules also twisted the side chains of Glu269 and Ile272 considerably. These residues are also part of the sugar-binding groove. The observed obstructive conformation of the side chain of Trp78 in the present structure is the exact opposite of the stacked conformation. This rarely observed conformation is stabilized by a number of hydrogen bonds between Trp78 and Asn79 through water molecules W49, W229, W269, W547 and W557.


    Organizational Affiliation

    Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Chitinase-3-like protein 1
A
361Ovis ariesMutation(s): 0 
Gene Names: CHI3L1
Find proteins for Q6TMG6 (Ovis aries)
Go to Gene View: CHI3L1
Go to UniProtKB:  Q6TMG6
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MAN
Query on MAN

Download SDF File 
Download CCD File 
A
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
NAG
Query on NAG

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Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
MPD
Query on MPD

Download SDF File 
Download CCD File 
A
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
EOH
Query on EOH

Download SDF File 
Download CCD File 
A
ETHANOL
C2 H6 O
LFQSCWFLJHTTHZ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.167 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 60.873α = 90.00
b = 66.415β = 90.00
c = 105.692γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
DENZOdata reduction
AMoREphasing
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-05-01
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance