The nucleotide sequence of the Ustilago maydis LEU1 gene has been dete
rmined. It contains a continuous open reading frame predicted to encod
e a protein of 773 amino acids with a molecular mass of 83 234 Da. The
protein is homologous to alpha-isopropylmalate isomerases from prokar
yotes and eukaryotes, as well as to other members of a family of struc
turally related isomerases.