Sequence analysis of a Dictyostelium discoideum gene coding for an active dihydroorotate dehydrogenase in yeast

A Dictyostelium discoideum DNA fragment isolated on the basis of its ability to complement the ural mutation of yeast, codes for a dihydroorotate dehydrogenase activity. The complete nucleotide sequence of this 1898 bp fragment has been determined and reveals an open reading frame capable of coding for a 369 amino acid polypeptide of molecular mass 47.000. The gene shows preferential use of codons with weak pairing forces. Eleven codons, mainly those with a G in the third position, are absent. The flanking sequences are unusually rich in A + T (80%). Several direct and inverted repeats exist in the 5' flanking sequence.