tetrahydrosulfopterin + L-serine => 5,10-methylenetetrahydrosulfopterin + glycine + H2O
tetrahydrosulfopterin + l-serine => 5,10-methylenetetrahydrosulfopterin + glycine + h2o
tetrahydrosulfopterin + L-serine => 5,10-methylenetetrahydrosulfopterin + glycine + H2O
tetrahydrosulfopterin + l-serine => 5,10-methylenetetrahydrosulfopterin + glycine + h2o