This family consists of several agglutinin-like proteins from different Candida species. ALS genes of Candida albicans encode a family of cell-surface glycoproteins with a three-domain structure. Each Als protein has a relatively conserved N-terminal domain, a central domain consisting of a tandemly repeated motif of variable number, and a serine-threonine-rich C-terminal domain that is relatively variable across the family. The ALS family exhibits several types of variability that indicate the importance of considering strain and allelic differences when studying ALS genes and their encoded proteins [1]. Fungal adhesins, which include sexual agglutinins, virulence factors, and flocculins, are surface proteins that mediate cell-cell and cell-environment interactions. It is possible that both the serine/threonine-rich domain and the cysteine residues in the C-terminal and DIPSY Pfam:PF11763 participate in anchoring the terminal domains inside the wall, so that only the inner part of Map4p, including the repeat region, is sticking out as a fold-back loop then able to act in adhesing [3].

1: The ALS5 gene of Candida albicans and analysis of the Als5p N-terminal domain. Hoyer LL, Hecht JE; Yeast 2001;18:49-60. PMID:11124701

2: The fission yeast Map4 protein is a novel adhesin required for mating. Sharifmoghadam MR, Bustos-Sanmamed P, Valdivieso MH; FEBS Lett. 2006;580:4457-4462. PMID:16857197

3: Molecular phylogenetics of ascomycotal adhesins-A novel family of putative cell-surface adhesive proteins in fission yeasts. Linder T, Gustafsson CM; Fungal Genet Biol. 2007; [Epub ahead of print] PMID:17870620