Crystal structure of the sulfoquinovosyl binding protein SmoF complexed with sulfoquinovosyl diacylglycerol

Experimental Data Snapshot

  • Resolution: 2.14 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.203 

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The sulfoquinovosyl glycerol binding protein SmoF binds and accommodates plant sulfolipids.

Snow, A.J.D.Sharma, M.Lingford, J.P.Zhang, Y.Mui, J.W.Epa, R.Goddard-Borger, E.D.Williams, S.J.Davies, G.J.

(2022) Curr Res Struct Biol 4: 51-58

  • DOI: https://doi.org/10.1016/j.crstbi.2022.03.001
  • Primary Citation of Related Structures:  
    7QHV, 7YZS, 7YZU

  • PubMed Abstract: 

    Sulfoquinovose (SQ) is the anionic headgroup of the ubiquitous plant sulfolipid, sulfoquinovosyl diacylglycerol (SQDG). SQDG can undergo delipidation to give sulfoquinovosyl glycerol (SQGro) and further glycoside cleavage to give SQ, which can be metabolized through microbial sulfoglycolytic pathways. Exogenous SQDG metabolites are imported into bacteria through membrane spanning transporter proteins. The recently discovered sulfoglycolytic sulfoquinovose monooxygenase (sulfo-SMO) pathway in Agrobacterium tumefaciens features a periplasmic sulfoquinovosyl glycerol binding protein, SmoF, and an ATP-binding cassette (ABC) transporter. Here, we use X-ray crystallography, differential scanning fluorimetry and isothermal titration calorimetry to study SQ glycoside recognition by SmoF. This work reveals that in addition to SQGro, SmoF can also bind SQ, a simple methyl glycoside and even a short-chain SQDG analogue. Molecular recognition of these substrates is achieved through conserved interactions with the SQ-headgroup together with more plastic interactions with the aglycones. This suggests that the solute binding protein of A. tumefaciens, and related SQ-binding proteins from other sulfoglycolytic pathways, can provide their host organisms direct access to most of the SQ metabolites known to be produced by phototrophs.

  • Organizational Affiliation

    York Structural Biology Laboratory, Department of Chemistry, University of York, York, YO10 5DD, UK.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Sulfoquinovosyl binding proteinA [auth AAA],
B [auth BBB]
396Agrobacterium tumefaciensMutation(s): 0 
Gene Names: SY94_3278
Find proteins for A9CEY9 (Agrobacterium fabrum (strain C58 / ATCC 33970))
Explore A9CEY9 
Go to UniProtKB:  A9CEY9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA9CEY9
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CQI (Subject of Investigation/LOI)
Query on CQI

Download Ideal Coordinates CCD File 
C [auth AAA],
E [auth BBB]
[(2~{S},3~{S},4~{S},5~{R},6~{S})-6-[(2~{S})-3-butanoyloxy-2-heptanoyloxy-propoxy]-3,4,5-tris(oxidanyl)oxan-2-yl]methanesulfonic acid
C32 H60 O12 S
Query on GLY

Download Ideal Coordinates CCD File 
C2 H5 N O2
Experimental Data & Validation

Experimental Data

  • Resolution: 2.14 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.203 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 53.215α = 90
b = 69.589β = 91.539
c = 104.574γ = 90
Software Package:
Software NamePurpose
Aimlessdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Leverhulme TrustUnited KingdomRPG-2017-190

Revision History  (Full details and data files)

  • Version 1.0: 2022-04-13
    Type: Initial release
  • Version 1.1: 2024-05-01
    Changes: Data collection, Derived calculations, Refinement description