4LHK

Structure of the N-terminal domain of the Lg-Flo1 adhesin (N-Lg-Flo1p) from the yeast Saccharomyces pastorianus, in complex with calcium and alpha-1,2-mannobiose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.73 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.137 
  • R-Value Observed: 0.140 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Molecular mechanism of flocculation self-recognition in yeast and its role in mating and survival.

Goossens, K.V.Ielasi, F.S.Nookaew, I.Stals, I.Alonso-Sarduy, L.Daenen, L.Van Mulders, S.E.Stassen, C.van Eijsden, R.G.Siewers, V.Delvaux, F.R.Kasas, S.Nielsen, J.Devreese, B.Willaert, R.G.

(2015) mBio 6: e00427-15

  • DOI: https://doi.org/10.1128/mBio.00427-15
  • Primary Citation of Related Structures:  
    4LHK, 4LHL, 4LHN

  • PubMed Abstract: 

    We studied the flocculation mechanism at the molecular level by determining the atomic structures of N-Flo1p and N-Lg-Flo1p in complex with their ligands. We show that they have similar ligand binding mechanisms but distinct carbohydrate specificities and affinities, which are determined by the compactness of the binding site. We characterized the glycans of Flo1p and their role in this binding process and demonstrate that glycan-glycan interactions significantly contribute to the cell-cell adhesion mechanism. Therefore, the extended flocculation mechanism is based on the self-interaction of Flo proteins and this interaction is established in two stages, involving both glycan-glycan and protein-glycan interactions. The crucial role of calcium in both types of interaction was demonstrated: Ca(2+) takes part in the binding of the carbohydrate to the protein, and the glycans aggregate only in the presence of Ca(2+). These results unify the generally accepted lectin hypothesis with the historically first-proposed "Ca(2+)-bridge" hypothesis. Additionally, a new role of cell flocculation is demonstrated; i.e., flocculation is linked to cell conjugation and mating, and survival chances consequently increase significantly by spore formation and by introduction of genetic variability. The role of Flo1p in mating was demonstrated by showing that mating efficiency is increased when cells flocculate and by differential transcriptome analysis of flocculating versus nonflocculating cells in a low-shear environment (microgravity). The results show that a multicellular clump (floc) provides a uniquely organized multicellular ultrastructure that provides a suitable microenvironment to induce and perform cell conjugation and mating. Yeast cells can form multicellular clumps under adverse growth conditions that protect cells from harsh environmental stresses. The floc formation is based on the self-interaction of Flo proteins via an N-terminal PA14 lectin domain. We have focused on the flocculation mechanism and its role. We found that carbohydrate specificity and affinity are determined by the accessibility of the binding site of the Flo proteins where the external loops in the ligand-binding domains are involved in glycan recognition specificity. We demonstrated that, in addition to the Flo lectin-glycan interaction, glycan-glycan interactions also contribute significantly to cell-cell recognition and interaction. Additionally, we show that flocculation provides a uniquely organized multicellular ultrastructure that is suitable to induce and accomplish cell mating. Therefore, flocculation is an important mechanism to enhance long-term yeast survival.


  • Organizational Affiliation

    Department of Bioengineering Sciences, Structural Biology Research Center, Vrije Universiteit Brussel, Brussels, Belgium.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Flocculin
A, B
239Saccharomyces pastorianusMutation(s): 0 
Gene Names: Lg-FLO1
UniProt
Find proteins for B3IUB3 (Saccharomyces pastorianus)
Explore B3IUB3 
Go to UniProtKB:  B3IUB3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB3IUB3
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose
C, D
2N/A
Glycosylation Resources
GlyTouCan:  G53402KW
GlyCosmos:  G53402KW
GlyGen:  G53402KW
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.73 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.137 
  • R-Value Observed: 0.140 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 38.618α = 90
b = 85.476β = 93.72
c = 68.24γ = 90
Software Package:
Software NamePurpose
BALBESphasing
REFMACrefinement
XDSdata reduction
Aimlessdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-09-24
    Type: Initial release
  • Version 1.1: 2015-05-06
    Changes: Database references
  • Version 1.2: 2015-06-03
    Changes: Database references
  • Version 1.3: 2015-12-02
    Changes: Database references
  • Version 1.4: 2016-06-08
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Database references, Derived calculations, Structure summary
  • Version 2.1: 2023-09-20
    Changes: Data collection, Database references, Refinement description, Structure summary