Responsible for transport of raffinose into the cell (PubMed:2556373, PubMed:18008022). Can also transport lactose and melibiose (PubMed:2556373). Has weak activity with maltose (PubMed:18008022). Monomer. Belongs to the major facilitator superfamily. Oligosaccharide:H(+) symporter (OHS) (TC 2.A.1.5) family.