The genes YNI1 and YNR1, encoding nitrite reductase and nitrate reductase respectively in the yeast Hansenula polymorpha, are clustered and co-ordinately regulated.

摘要: The nitrite reductase-encoding gene (YNI1) from the yeast Hansenula polymorpha was isolated a lambda EMBL3 H. genomic DNA library, using as probe 481 bp fragment of Aspergillus nidulans encoding reductase (niiA). An open reading frame 3132 bp, putative protein 1044 amino acids with high similarity reductases fungi, located by sequencing in phages lambdaNB5 and lambdaJA13. Genes YNI1 YNR1 (encoding nitrate reductase) are clustered, separated 1700 bp. Northern blot analysis showed that expression is co-ordinately regulated; induced repressed sources reduced nitrogen, even presence nitrate. A mutant lacking activity obtained deletion chromosomal copy YNI1. does not grow or nitrite; it exhibits similar level transcription to wild type, but enzymic only about 50% type. In delta ynil::URA3 extrudes approx. 24 nmol nitrite/h per mg (wet weight), five times more than