Mating type proteins are sequence specific DNA-binding proteins that act as master switches in yeast differentiation by controlling gene expression in a cell type-specific fashion. Only present in a-cells (classes I and IV). There are three genetic loci for mating type genes in C.glabrata. MTL1 seems to be the expression locus that determines the mating type of the cell, whereas MTL2 (containing MTL2A1) and MTL3 (containing MTL3ALPHA1 and MTL3ALPHA2) appear to represent silenced repositories of mating type information. Haploid C.glabrata strains can switch mating type, however, neither mating nor diploid forms of C.glabrata have been observed so far. Belongs to the MATA1 family. It is uncertain whether Met-1 or Met-2 is the initiator.