Molecular phylogeny of pectinase genes PGU in the yeast genus Saccharomyces

Using yeast genome databases and literature data, phylogenetic analysis of pectinase PGU genes from 112 Saccharomyces strains assigned to the biological species S. arboricola , S. bayanus (var. uvarum ), S. cariocanus , S. cerevisiae , S. kudriavzevii , S. mikatae , S. paradoxus , and the hybrid taxon S. pastorianus (syn. S. carlsbergensis ) was carried out. A superfamily of divergent PGU genes was found. Natural interspecies transfer of the PGU gene both from S. cerevisiae to S. bayanus and from S. paradoxus to S. cerevisiae may, however, occur. Within the Saccharomyces species, identity of the PGU nucleotide sequences was 98.8–100% for S. cerevisiae , 86.1–95.7% for S. bayanus (var. uvarum ), 94–98.3% for S. kudriavzevii , and 96.8–100% for S. paradoxus / S. cariocanus . For the first time, a family of polymeric PGU1b , PGU2b , PGU3b and PGU4b genes is documented for the yeast S. bayanus var. uvarum , a variety important for winemaking.