S-methylmercury-L-cysteine(out) + L-methionine(in) <=> S-methylmercury-L-cysteine(in) + L-methionine(out)
s-methylmercury-l-cysteine(out) + l-methionine(in) <=> s-methylmercury-l-cysteine(in) + l-methionine(out)