Characterization of the histidine mutants of Kluyveromyces lactis

Thirty-eight different histidine mutations of Kluyveromyces lactis were iso lated and genetically characterized. All of the mutations were nuclear rece ssive alleles. They turned out to belong to seven different complementation groups, designated hisA1 to hisA7. Five of these genes have been cloned by in vivo complementation of the Klhis mutations. Their homology to some of the histidine genes of Saccharomyces cerevisiae was confirmed by heterologo us complementation. However, one of these KlHIS genes did not complement an y mutation in the seven known histidine biosynthetic enzymes encoding genes (his1-his7) of S. cerevisiae. Copyright (C) 1999 John Wiley & Sons, Ltd.