The sequence of 8.8 kb of yeast chromosome III cloned in lambda PM3270 contains an unusual long ORF (YCR601)

Identification of the murine beige gene by YAC complementation and positional cloning

The beige mutation is a murine autosomal recessive disorder, resulting in hypopigmentation, bleeding and immune cell dysfunction. The gene defective in beige is thought to be a homologue of the gene for the human disorder Chediak-Higashi syndrome. We have identified the murine beige gene by in vitro complementation and positional cloning, and confirmed its identification by defining mutations in two independent mutant alleles. The sequence of the beige gene message shows strong nucleotide homology to multiple human ESTs, one or more of which may be associated with the Chediak-Higashi syndrome gene. The amino acid sequence of the Beige protein revealed a novel protein with significant amino acid homology to orphan proteins identified in Saccharomyces cerevisiae, Caenorhabditis elegans and humans.

Nucleotide sequence of 9.2 kb left of CRY1 on yeast chromosome III from strain AB972: evidence for a Ty insertion and functional analysis of open reading frame YCR28

We report the 9210 bp sequence from a segment of yeast chromosome III cloned from strain AB972 in lambda PM3270. Analysis of this sequence and its comparison with the one derived from the corresponding segment of strain XJ24-24A revealed that the AB972 region contains a duplication of about 2 kb and a Ty element, which are not found in XJ24-24A and cause a quite significant rearrangement of the whole region. We performed functional analysis of YCR28, the largest open reading frame we found in both AB972 and XJ24-24A. YCR28 encodes a putative protein of 512 amino acids with some similarities to yeast allontoate permease. Its disruption does not cause any detectable phenotype on rich medium or on allantoate medium, while we observed a strain-dependent effect on sensitivity to amino acid balance and to 3-aminotriazole, when cells were grown in synthetic medium.

The complete DNA sequence of yeast chromosome III

The entire DNA sequence of chromosome III of the yeast Saccharomyces cerevisiae has been determined. This is the first complete sequence analysis of an entire chromosome from any organism. The 315-kilobase sequence reveals 182 open reading frames for proteins longer than 100 amino acids, of which 37 correspond to known genes and 29 more show some similarity to sequences in databases. Of 55 new open reading frames analysed by gene disruption, three are essential genes; of 42 non-essential genes that were tested, 14 show some discernible effect on phenotype and the remaining 28 have no overt function.