Abstract
In Saccharomyces cerevisiae, the SCLl-1 mutation is a dominant suppressor of the cycloheximide-resistant, temperature-sensitive (ts) lethal mutation, crl3 [McCusker and Haber, Genetics 119 (1988a) 303–315]. The wild-type scl1+ gene was isolated by screening subclones of the 35-kb region between TRP5 and LEU1 for restoration of the ts phenotype in an SCLl-l crl3-2 strain. The sell + mRNA is about 900 nt long and encodes an open reading frame of 810 bp. The polypeptide deduced from sell + possesses a putative secretory signal peptide. The 5'-noncoding region may be under multiple controls, since it contains significant homology to the consensus sequences for the DNA-binding proteins, GCN4, GFI and, possibly, TUF. Gene disruption of sell + demonstrates that it is an essential gene.