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