4LHL

Structure of the N-terminal domain of the Flo1 adhesin (N-Flo1p) from the yeast Saccharomyces cerevisiae

Summary for 4LHL

• Entry DOI: 10.2210/pdb4lhl/pdb
• Related: 4LHk 4LHn
• Descriptor: Flocculation protein FLO1, SODIUM ION (3 entities in total)
• Functional Keywords: pa14 domain, cell adhesion
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Cellular location: Cell membrane; Lipid-anchor, GPI-anchor: P32768
• Total number of polymer chains: 1
• Total formula weight: 28485.28

Authors

Ielasi, F.S.,Willaert, R.G. (deposition date: 2013-07-01, release date: 2014-09-24, Last modification date: 2024-11-06)

Primary citation

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.
Molecular mechanism of flocculation self-recognition in yeast and its role in mating and survival.
MBio, 6:e00427-15-, 2015

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.

PubMed: 25873380
DOI: 10.1128/mBio.00427-15

Experimental method

X-RAY DIFFRACTION (1.43 Å)