Complex evolution of the DAL5 transporter family.
BACKGROUND: Genes continuously duplicate and the duplicated copies remain in the genome or get deleted. The DAL5 subfamily of transmembrane transporter genes has eight known members in S. cerevisiae. All are putative anion:cation symporters of vitamins (such as allantoate, nicotinate, panthotenate and biotin). The DAL5 subfamily is an old and important group since it is represented in both Basidio