melibiose(in) + H(+)(in) <=> melibiose(out) + H(+)(out)
melibiose(in) + h(+)(in) <=> melibiose(out) + h(+)(out)
melibiose(in) + H(+)(in) <=> melibiose(out) + H(+)(out)
melibiose(in) + h(+)(in) <=> melibiose(out) + h(+)(out)