Sequencing and analysis of 51·6 kilobases on the left arm of chromosome XI from Saccharomyces cerevisiae reveals 23 open reading frames including the FAS1 gene

We have sequenced two segments containing a total of 51·6 kb of the left arm from chromosome XI of Saccharomyces cerevisiae. The first segment of 38·5 kb contains 18 open reading frames (ORFs) of more than 100 amino acid residues. Five ORFs encode known yeast genes, including the fatty acid synthase gene (FAS1). Three new yeast genes were discovered with homologies to non-yeast genes and ten new genes without homologies to any known sequences. The second segment of 13 kb contains five ORFs with two known yeast genes and three unknown genes. The sequences from cosmid pUKG041 were obtained entirely with the walking primer strategy resulting in a very low overall sequence redundancy of 2·8 and an average reading length of 443 bases.     

Analysis of a 26 756 bp segment from the left arm of yeast chromosome IV

The nucleotide sequence of a 26·7 kb DNA segment from the left arm of Saccharomyces cerevisiae chromosome IV is presented. An analysis of this segment revealed 11 open reading frames (ORFs) longer than 300 bp and one split gene. These ORFs include the genes encoding the large subunit of RNA polymerase II, the biotin apo-protein ligase, an ADP-ribosylation factor (ARF 2), the ‘L35’-ribosomal protein, a rho GDP dissociation factor, and the sequence encoding the protein phosphatase 2A. Further sequence analysis revealed a short ORF encoding the ribosomal protein YL41B, an intron in a 5′ untranslated region and an extended homology with another cosmid (X83276) located on the same chromosome. The potential biological relevance of these findings is discussed. The sequence was submitted to the EMBL database under Accession Number X96876.     

II. Yeast sequencing reports. Sequence analysis of a 78·6 kb segment of the left end of Saccharomyces cerevisiae chromosome II

We report the sequence analysis of a 78,601 bp DNA segment on the left arm of chromosome II of Saccharomyces cerevisiae. This 78·6 kb segment spans the region from the start of a subtelomeric Y′ element up to the ILS1 gene. It contains 49 open reading frames (ORFs) with more than 100 amino acids length including 14 internal and five overlapping ORFs. The gene density, excluding the internal ORFs, was calculated as one ORF per 2·2 kb. Eight ORFs (PKC1, TyA, TyB, ATP1, ROX3, RPL17a, PET112 and ILS1) correspond to previously characterized genes. ORF YBL0718 was identified as CDC27; YBL0706 as TEL1. Four other ORFs show strong similarities to already known genes. The gene product of YBL0838 is 60% identical to the ribosomal protein RPL32 from rat, mouse and man. YBL0701 encodes a protein with significant similarity to the initiation factor eIF2 associated p67 glycoprotein from rat. Eight ORFs were disrupted and the resulting yeast strains analysed with respect to their phenotype. The sequence has been deposited in the EMBL Nucleotide Sequence Database under the Accession Number X79489.     

XIV. Yeast sequencing reports. Twelve open reading frames revealed in the 23·6 kb segment flanking the centromere on the Saccharomyces cerevisiae chromosome XIV right arm

The nucleotide sequence of 23·6 kb of the right arm of chromosome XIV is described, starting from the centromeric region. Both strands were sequenced with an average redundancy of 4·87 per base pair. The overall G+C content is 38·8% (42·5% for putative coding regions versus 29·4% for non-coding regions). Twelve open reading frames (ORFs) greater than 100 amino acids were detected. Codon frequencies of the twelve ORFs agree with codon usage in Saccharomyces cerevisiae and all show the characteristics of low level expressed genes. Five ORFs (N2019, N2029, N2031, N2048 and N2050) are encoded by previously sequenced genes (the mitochondrial citrate synthase gene, FUN34, RPC34, PRP2 and URK1, respectively). ORF N2052 shows the characteristics of a transmembrane protein. Other elements in this region are a tRNA^Pro gene, a tRNA^Asn gene, a τ₃₄ and a truncated δ₃₄ element. Nucleotide sequence comparison results in relocation of the SIS1 gene to the left arm of the chromosome as confirmed by colinearity analysis. The nucleotide sequence data reported in this paper will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession number X77395.     

VI. Yeast sequencing reports. Sequencing of an 18·8 kb fragment from Saccharomyces cerevisiae chromosome VI

The nucleotide sequence of lambda phage clone 4121, which contains the 18·8 kb fragment of Saccharomyces cerevisiae chromosome VI left arm, was determined. This sequence had seven open reading frames (ORFs), four of which were identical to known genes (ACT1, YPT1, TUB2 and RPO41). Another three ORFs (4121orfR003, 4121orfR004 and 4121orfRN001) were highly homologous to FET3 multi-copper oxidase, glucose transport protein, and hypothetical protein of YIL106w on chromosome IX, respectively. 4121orfRN01 is suggested to contain an intron. The sequence has been submitted to DDBJ/EMBL/GenBank data library under Accession Number D44598.     

A 12·8 kb segment,on the right arm of chromosome II from Saccharomyces cerevisiae including part of the DUR1, 2 gene,contains five putative new genes

A 12 820 bp fragment from the right arm of chromosome II of Saccharomyces cerevisiae was sequenced and analysed. This fragment contains six non-overlapping long open reading frames (ORFs) designated from the centromere- to the telomere-proximal ends as: YBR1441, 1443, 1444, 1445, 1446 and 1448. YBR1441 encodes a polypeptide of 845 amino acids which shares a long consensus domain with products of S. cerevisiae MCM2, MCM3, CDC46 and Schizosaccharomyces pombe cdc21⁺ genes. These genes are involved in DNA replication. YBR1445 encodes a polypeptide of 404 amino acids which has strong similarity with the S. cerevisiae KRE2/MNT1, YUR1, KTR1 gene products. The KRE2/MNT1 protein is an α-1,2-mannosyltransferase. The product of YBR1444, which encodes a protein of 375 amino acids, presents a lipase signature sequence and a peroxisomal targeting signal. YBR1448, whose sequence extends further on the telomere-proximal end of the fragment, is identical to the 3′ end of the DUR1,2 gene encoding urea amidolyase. The two ORFs, YBR1443 and YBR1446, exhibit no significant similarity with any known gene.     

Sequence of a 39 411 bp DNA fragment covering the left end of chromosome VII of Saccharomyces cerevisiae

We have sequenced a DNA fragment of 39 411 bp which includes part of the left telomere of chromosome VII of Saccharomyces cerevisiae. We have identified 19 open reading frames (ORFs); six correspond to known yeast genes (ADH4, FZF1, HKB, RTG2, HFM1 and PDE1), nine have similarity with other genes and four exhibit no significant similarity with any known gene. The average size of these ORFs seems to be related to their location, the eight ORFs nearest the telomere being shorter than the 11 others. These two groups of genes are separated by a region of 4·5 kb devoid of significant ORFs. One ORF, NRF120, is a new member of the seripauperine family, represented once in all sequenced yeast chromosomes, in a subtelomeric location. This sequence has been entered in the EMBL data library under accession number X94357.     

VII. Yeast sequencing reports. The sequence of an 11·1 kb fragment on the left arm of Saccharomyces cerevisiae chromosome VII reveals six open reading frames including NSP49, KEM1 and four putative new genes

We report the sequence of an 11·1 kb fragment located on the left arm of chromosome VII of Saccharomyces cerevisiae. By sequence analysis we have detected six open reading frames (ORFs) longer than 300 bp, which cover 87% of the entire sequence. ORF G1645 is 100% identical to the KEM1 gene, also identified as DST2, XRN1, SEP1 and RAR5, while G1648 is 100% identical to the NSP49 or NUP49 gene. ORF G1642 shares some identity with a hypothetical protein of Caenorhabditis elegans, while the other four ORFs show no significant homology to known proteins. The sequence has been submitted to the EMBL data library under Accession Number X84705.     

The sequence of 36·8 kb from the left arm of chromosome XIV reveals 24 complete open reading frames: 18 correspond to new genes,one of which encodes a protein similar to the human myotonic dystrophy kinase

We have determined the complete nucleotide sequence of a 36·8 kb segment from the left arm of chromosome XIV carried by the cosmid 14–11. The sequence encodes the 5′ coding region of the PSD1 gene, the 3′ coding region of an unknown gene and 24 complete open reading frames, of which 18 correspond to new genes and six (SKO1, SCL41A, YGP1, YCK2, RPC31 and MFA2) have been sequenced previously. Of the 24 new genes, five show significant similarities to sequences present in the databanks. These include elongation factors 2 and the human myotonic dystrophy kinase. The sequence has been deposited in the EMBL databank under the Accession Number X92517.     

Sequencing and functional analysis of a 32 560 bp segment on the left arm of yeast chromosome II. Identification of 26 open reading frames,including the KIP1 and SEC17 genes

We report here the DNA sequence of a segment (α1006.13: YBLO5) of chromosome II of Saccharomyces cerevisiae, extending over 32·5 kb. The segment contains 26 open reading frames (ORFs) from YBLO501 to YBLO526. YBL0505 corresponds to the SEC17 gene and YBL0521 to the KIP1 gene. YBL0516 contains an intron, YBL0513 shows homology with the RAT protein phosphatase and YBL0526 contains a zinc-finger motif. Disruption of 14 genes by insertion of a URA3 cassette has been performed and these mutants were analysed for their mating and sporulation ability, and for their growth on different carbon sources. YBL0515 and YBL0526 ORFs seem to be involved in the sporulation process.     

Sequencing of a 17·6 kb segment on the right arm of yeast chromosome VII reveals 12 ORFs,including CCT,ADE3 and TR-I genes,homologues of the yeast PMT and EF1G genes,of the human and bacterial electron-transferring flavoproteins (β-chain) and of the Escherichia coli phosphoserine phosphohydrolase,and five new ORFs

A 17·6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been sequenced and analysed. The sequence contains twelve open reading frames (ORFs) longer than 100 amino acids. Three genes had already been cloned and sequenced: CCT, ADE3 and TR-I. Two ORFs are similar to other yeast genes: G7722 with the YAL023 (PMT2) and PMT1 genes, encoding two integral membrane proteins, and G7727 with the first half of the genes encoding elongation factors 1γ, TEF3 and TEF4. Two other ORFs, G7742 and G7744, are most probably yeast orthologues of the human and Paracoccus denitrificans electron-transferring flavoproteins (β chain) and of the Escherichia coli phosphoserine phosphohydrolase. The five remaining identified ORFs do not show detectable homology with other protein sequences deposited in data banks. The sequence has been deposited in the EMBL data library under Accession Number Z49133.     

The sequence of a 24 152 bp segment from the left arm of chromosome XIV from Saccharomyces cerevisiae between the BNI1 and the POL2 genes

In the framework of the European Union programme for sequencing the genome of Saccharomyces cerevisiae we have determined the nucleotide sequence of a region of 24 152 bp located on the left arm of chromosome XIV between the BNI1 and the POL2 genes. The sequence was obtained by directed sequence analysis using a mixture of ExoIII and primer walking strategies. Subsequent analysis revealed 13 open reading frames (ORFs) including four small ORFs completely internal to, or partly overlapping with, other ORFs. Five of these ORFs have been described previously (BNI1, APL1, LYP1, PIK1, POL2) and thus 74·8% of the 24 152 bp were already present in the databases prior to this sequencing effort. Interestingly, all 13 identified ORFs are characterized by a low codon adaptation index (0·04–0·22). In addition, this region of chromosome XIV shows an unusually high gene density with about 88% of coding DNA. This amounts to one gene per 2177 bp, which is significantly above the average gene length (about 1500 bp). For eight ORFs considerable homologies to ‘Expressed Sequence Tags’ derived from human cDNAs located in the XREF database could be identified. The complete nucleotide sequence of the 24 152 bp segment has been deposited in the EMBL data library under the Accession Number X92494.     

Recovery of gene function by gene duplication in Saccharomyces cerevisiae

A prototroph revertant (Rev9) selected from an ATCase^? mutant of the URA2 gene containing three nonsense mutations was shown to contain two ATCase coding sequences. We cloned both ATCase coding areas to show that the duplicated locus (dl9) was the only functional one. Its size corresponded roughly to the second half of the URA2 wild-type gene. Sequence analysis of the 5′ end of dl9 indicated that this duplicated sequence was inserted within the intergenic region close to the MRS3 gene and was transcribed from an unknown promoter divergently from the MRS3 gene. The event leading to the revertant strain Rev9 included a rearrangement that increased the size of chromosome X by about 60 kb. In agreement with such a rearrangement, recombination was undetectable in the vicinity of the locus dl9. Genetic mapping confirms that the MRS3 gene is 2 cM distal to the URA2 gene on the right arm of chromosome X.     

XV. Yeast sequencing reports. A 29·425 kb segment on the left arm of yeast chromosome XV contains more than twice as many unknown as known open reading frames

The nucleotide sequence of a 29·425 kb fragment localized on the left arm of chromosome XV from Saccharomyces cerevisiae has been determined. The sequence contains 13 open reading frames (ORFs) of which four encode the known genes ADH1, COQ3, MSH2 and RCF4. Predictions are made concerning the functions of the unknown ORFs. Some of the ORFs contain sequences similar to expressed sequences tags (EST) found in the database made available by TIGR. In particular, the highly expressed ADH1 gene is represented in this database by no less than 20 EST sequences. Two ARS sequences and a putative functional GCN4 motif have also been detected. One ORF (O0953) containing nine putative transmembrane segments is similar to a hypothetical membrane protein of Arabidopsis thaliana. Characteristic features of the other ORFs include ATP/GTP binding sites, a fungal Zn(2)-Cys(6) binuclear centre, an endoplasmic reticulum targeting sequence, a β-transducin repeat signature and in two instances, good similarity to the prokaryotic lipoprotein signal peptide motif. The sequence has been deposited in the EMBL data library under Accession Number X83121.     

Sequencing of a 9·2 kb telomeric fragment from the right arm of Saccharomyces cerevisiae chromosome XIV

We report the complete sequence of a 9·2 kb fragment next to and including the right telomere of Saccharomyces cerevisiae chromosome XIV. Four open reading frames (ORFs) longer than 100 amino acids were observed in the sequenced segment. One ORF (378 codons) does not show any significant homology with proteins in the databases and corresponds to a putative new gene. Two ORFs are almost identical to the known YCR007/YKL219 and PAU1-like hypothetical protein families already identified on several S. cerevisiae chromosomes. These ORFs, whose function is unknown, are generally associated with sub-telomeric regions of chromosomes. The fourth one shows significant identities with bacterial mannitol dehydrogenases. It could be a yeast gene implicated in the metabolism of mannitol (or a related substrate). The sequence has been deposited in the EMBL data library under Accession Number X86790.     

The sequence of a 17 933 bp segment of Saccharomyces cerevisiae chromosome XIV contains the RHO2, TOP2, MKT1 and END3 genes and five new open reading frames

We report the DNA sequence of a 17 933 bp fragment from the left arm of chromosome XIV of Saccharomyces cerevisiae. Analysis of the sequence reveals the presence of ten open reading frames (ORFs) larger than 100 codons. Four of these were previously identified as genes RHO2, TOP2, MKT1 and END3. Additionally, the NH₂ end coding region of PMS1 is found in the 3′ end of the sequence. No significant homology to any known protein has been found for the other five ORFs. The nucleotide sequence has been deposited at EMBL, with Accession Number X89016.     

VIV. Yeast sequencing reports. Sequencing analysis of a 24·7 kb fragment of yeast chromosome XIV identifies six known genes,a new member of the hexose transporter family and ten new open reading frames

The DNA sequence of a 24·7 kb region covering the left arm of chromosome XIV from Saccharomyces cerevisiae was determined. This region contains 17 open reading frames (ORFs) which code for proteins of more than 100 amino acids. Five ORFs correspond to the KRE1, ATP11, DAL82, RFA2 and MCK1 loci, described previously. Two ORFs present high similarity to known proteins: NO345 with the hexose transporter family, and NO351 with the yeast chorismate mutase/prephenate dehydratase enzyme encoded by PHA2. Six ORFs show limited similarity with known proteins or some specific features: NO339 presents 11 potential transmembrane domains. NO343, which is internal to NO345, presents a putative signal sequence and a potential transmembrane domain. NO348 shows similarity with YCW2, TUP1 and SEC13. NO364 reveals a signature for a pyridoxal-phosphate attachment site. Finally, NO384 and NO388 present a biased amino acid composition, being rich in Asn or Glu/Lys/Arg, respectively. Four other ORFs (NO342, NO376, NO381 and NO397) show no similarity to proteins within the databases screened. The sequence has been entered in the EMBL data library under Accession Number Z46259.     

Sequencing and analysis of 51 kb on the right arm of chromosome XV from Saccharomyces cerevisiae reveals 30 open reading frames

We have sequenced a region of 51 kb of the right arm from chromosome XV of Saccharomyces cerevisiae. The sequence contains 30 open reading frames (ORFs) of more than 100 amino acid residues. Thirteen new genes have been identified. Thirteen ORFs correspond to known yeast genes. One delta element and one tRNA gene were identified. Upstream of the RPO31 gene, encoding the largest subunit of RNA polymerase III, lies a Abf1p binding site. The nucleotide sequence data reported in this paper are available in the EMBL, GenBank and DDBJ nucleotide sequence databases under the Accession Number X90518.