THE NEUROSPORA-CRASSA ERG3 GENE ENCODES A PROTEIN WITH SEQUENCE HOMOLOGY TO BOTH YEAST STEROL C-14 REDUCTASE AND CHICKEN LAMIN B-RECEPTOR

The erg3 gene of Neurospora crassa was sequenced (EMBL accession no. X 77955) and found to encode a protein of 490 amino acid residues with s ignificant homology to the yeast sterol biosynthetic enzyme C-14 reduc tase (39% identity) and also to the C-terminal region in the sequence reported for the chicken lamin B receptor (41% identity). The possibil ity that a single protein may possess both lamin B receptor and sterol C-14 reductase functions might account for non-sterol-biosynthetic ef fects of mutations in sterol biosynthesis genes and of inhibitors of s terol biosynthetic enzymes.