II. Yeast sequencing reports. A 12·5 kb fragment of the yeast chromosome II contains two adjacent genes encoding ribosomal proteins and six putative new genes, one of which encodes a putative transcriptional factor

Abstract

The nucleotide sequence of a 12.5 kb fragment localized to the right arm of chromosome II of Saccharomyces cerevisiae has been determined. The sequence contains eight putative genes. Two of them are contiguous and represent two ribosomal protein genes: SUP46 and URP1. SUP46 is implicated in translation fidelity and encodes the ribosomal protein S13. URP1 is homologous to the rat ribosomal protein gene L21. The open reading frame (ORF) YBR1245 is similar in its N-terminal part to transcription factors like SRF and MCM1. The ORF YBR1308 shows homology with proteins of the AAA-family (ATPases Associated with diverse cellular Activities). Two genes are predicted to encode putative membrane proteins.

SDC25, a dispensable Ras guanine nucleotide exchange factor of Saccharomyces cerevisiae differs from CDC25 by its regulation.

“…SDC25 mRNA was expressed when cells were shifted from glucose to ethanol (Figure 2) and continued to be accumulated with ethanol as a carbon source. During the transition, a gene encoding a ribosomal protein URPI (Demolis et al, 1995) was transiently repressed and re-expressed to a lower level than on glucose, which is the behavior described for many genes encoding ribosomal proteins (Wool- (Sikorski and Hieter, 1989) The whole CDC25 ORF in pKS (Kaplon and Jacquet, 1995) pBM1 CDC25 5' part (SALI-BamHI) from pL25a (Camonis et al, 1986) In olCS2 reverse, the nucleotides +5037 to +5002 of CDC25 are fused to nucleotides +4002 to +3990 of SDC25.…”

MBA1 encodes a mitochondrial membrane‐associated protein required for biogenesis of the respiratory chain

“…The gene also suppresses real-null and afg3/rcal double mutations (data not shown). MBA1 encodes a putative 278 amino acid protein whose N-terminal sequence has all the characteristics of cleavable mitochondrial targeting sequences [10] (Fig. 1).…”

“…By examining the function of genes that can bypass AFG3 when overexpressed, we aimed to better define the primary defect caused by inactivation of AFG3. One of these afg3-null suppressors is MBA1 (Multi-copy Bypass of AFG3), whose sequence was identified previously in the yeast sequencing project (YBR1307 in [10]), but whose function was unknown. Here, we present a further characterization of MBA1 and its gene product.…”

Three genes for mitochondrial proteins suppress null-mutations in both Afg3 and Rca1 when over-expressed

“…This subclone has afg3-null suppressor activity and contains three complete ORFs. YBR1305 and YBR1306 are named according to Demolis et al (1994). In that reference, MBA1 is termed YBR1307.…”

“…The third insert was hybridized to a chromosome blot, and found to be homologous to sequences on chromosome II (data not shown). The sequence of the insert of plasmid pJN-C1 was kindly provided by M. Jacquet and was later published as a contribution to the chromosome-II sequencing project (Demolis et al 1994).…”