1.3.1.14 - 390928 1.3.1.14 expressed in Escherichia coli strain MC1061 390917 1.3.1.14 expression in Escherichia coliBL21 DE3, expression of pyrDI alone and coexpression with pyrDII 390928 1.3.1.14 genes encoding the two alpha and beta polypeptides, expression in Escherichia coli 390568 1.3.1.14 two different genes 390917