Disruption and functional analysis of six ORFs of chromosome IV: YDL103c (QRI1), YDL105w (QRI2), YDL112w (TRM3), YDL113c, YDL116w (NUP84) and YDL167c (NRP1).

We have disrupted six ORFs (YDL103c, YDL105w, YDL112w, YDL113c, YDL116w and YDL167c) located on the left arm of chromosome IV. Except for YDL112w, the short flanking homology strategy was used to construct disruption cassettes using the KanMX4 marker. For YDL112w, a disruption cassette including the LEU2 gene was made.

Molecular characterization of germline NF2 gene rearrangements.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disease that causes a predisposition to nervous system tumors. Deleterious point mutations have been found in about 55% of NF2 patients, and large genomic deletions account for approximately 33% of NF2 gene alterations. The majority of these deletions are larger than 50 kb, with a breakpoint usually lying outside the NF2 gene.

NF2 gene in neurofibromatosis type 2 patients.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder that predisposes to nervous system tumors. The schwannomin (also termed merlin) protein encoded by the NF2 gene shows a close relationship to the family of cytoskeleton-to-membrane proteins linkers ERM (ezrin-radixin-moesin proteins). Even though penetrance of the disease is >95% and no genetic heterogeneity has been described, point mutations in the NF2 gene have been observed in only 34-66% of the screened NF2 patients, depending on the series.

A circular plasmid from the yeast Torulaspora delbrueckii.

A new member of the 2-micron family of plasmids, named pTD1, was found in the yeast Torulaspora delbrueckii, a widespread yeast associated with food. Nucleotide sequences revealed the presence of a pair of inverted repeats and three open reading frames, one of which is a homologue of the FLP recombinase gene of 2-micron plasmid. An ARS region was identified, by replication in Saccharomyces cerevisiae and T.

DNA sequence analysis of the VPH1-SNF2 region on chromosome XV of Saccharomyces cerevisiae.

The nucleotide sequence of a 37 000 base pair region from the left arm of chromosome XV of Saccharomyces cerevisiae has been determined and analysed. This region contains 21 open reading frames (ORFs) coding for proteins of more than 100 amino acids. Six ORFs correspond to the genes PAC1, VPH1, MOD5, CAP20, ORF1 and SNF2 already described.

Complete DNA sequence of yeast chromosome XI.

The complete DNA sequence of the yeast Saccharomyces cerevisiae chromosome XI has been determined. In addition to a compact arrangement of potential protein coding sequences, the 666,448-base-pair sequence has revealed general chromosome patterns; in particular, alternating regional variations in average base composition correlate with variations in local gene density along the chromosome. Significant discrepancies with the previously published genetic map demonstrate the need for using independent physical mapping criteria.

Genes of the linear mitochondrial DNA of Williopsis mrakii: coding sequences for a maturase-like protein, a ribosomal protein VAR1 homologue, cytochrome oxidase subunit 2 and methionyl tRNA.

The mitochondrial DNA (mtDNA) in some yeasts has a linear structure with inverted terminal repeats closed by a single-stranded loop. These mtDNAs have generally a constant gene order, beginning with a small ribosomal RNA gene at the right end and terminating with a cytochrome oxidase subunit 2 gene (COX2) at the left end, independently of the wide variation in genome size. In the mtDNAs from several species of the genus Williopsis, we found an additional open reading frame, ORF1, which was homologous to the Saccharomyces cerevisiae RF1 gene encoding a group I intron maturase-like protein.

The DNA sequence analysis of the HAP4-LAP4 region on chromosome XI of Saccharomyces cerevisiae suggests the presence of a second aspartate aminotransferase gene in yeast.

The nucleotide sequence of a 19,000 base pair region from the left arm of chromosome XI of Saccharomyces cerevisiae has been determined and analysed. It covers the HAP4-GFA1-LAP4 loci already described. As expected HAP4, GFA1 and LAP4 genes have been found and six new open reading frames (ORFs) with a coding capacity of more than 100 amino acid residues have been identified.

DNA sequence analysis of a 17 kb fragment of yeast chromosome XI physically localizes the MRB1 gene and reveals eight new open reading frames, including a homologue of the KIN1/KIN2 and SNF1 protein kinases.

We report in this paper the sequence of a part of chromosome XI of Saccharomyces cerevisiae. This 17 kbp nucleotide sequence represents the right half of cosmid pUKG151 and contains nine open reading frames, YKL453, 450, 449, 448, 445, 443, 442, 441 and the 5' part of YKL440. YKL440 was previously identified as the MBR1 gene and plays a role in mitochondrial biogenesis.

Diphthamide synthesis in Saccharomyces cerevisiae: structure of the DPH2 gene.

A gene involved in diphthamide biosynthesis, DPH2, was cloned from Saccharomyces cerevisiae by complementation of a diphthamide mutant. DPH2 exists as a single-copy gene in the yeast genome and is located on the left arm of chromosome XI. Sequence analysis of the DPH2 locus predicts that the DPH2 gene product is a 534-amino acid (aa) protein, with a calculated M(r) of 59,772.

DNA sequence analysis of the YCN2 region of chromosome XI in Saccharomyces cerevisiae.

A 6.8 kbp DNA fragment localized to the left arm of chromosome XI from Saccharomyces cerevisiae was sequenced and analysed (EMBL accession no. X69765).

Linear mitochondrial DNAs of yeasts: closed-loop structure of the termini and possible linear-circular conversion mechanisms.

The terminal structure of the linear mitochondrial DNA (mtDNA) from three yeast species has been examined. By enzymatic digestion, alkali denaturation, and sequencing of cloned termini, it was shown that in Pichia pijperi and P. jadinii, both termini of the linear mtDNA were made of a single-stranded loop covalently joining the two strands, as in the case of vaccinia virus DNA.

Linear mitochondrial DNAs of yeasts: frequency of occurrence and general features.

In most yeast species, the mitochondrial DNA (mtDNA) has been reported to be a circular molecule. However, two cases of linear mtDNA with specific termini have previously been described. We examined the frequency of occurrence of linear forms of mtDNA among yeasts by pulsed-field gel electrophoresis.

Analysis of the MSS51 region on chromosome XII of Saccharomyces cerevisiae.

We have localized gene MSS51 on chromosome XII of Saccharomyces cerevisiae between the RDN1 and CDC42 loci. 'Head to head' with MSS51 is another gene, QRI5, the function of which is unknown. However, the proximity of these genes, the structure of the intergenic region and the presence of an ABF1 binding site right in the middle of this region suggest that the MSS51 and QRI5 expressions are submitted to a common regulatory process.

Sequence of the HMR region on chromosome III of Saccharomyces cerevisiae.

A 10,095 base pair DNA fragment from the right arm of chromosome III of Saccharomyces cerevisiae has been sequenced and analysed. It encompasses the silent mating-type locus HMR. Both HMRa1 and HMRa2 genes, as well as their flanking regulatory regions, have been identified.

Sequence of the sup61-RAD18 region on chromosome III of Saccharomyces cerevisiae.

A 7965 bp DNA segment from the right arm of chromosome III of Saccharomyces cerevisiae, encompassing the sup61 and RAD18 genes, was sequenced. Four new open reading frames were found in this DNA fragment. One of them, YCR103, is 51% homologous with the G10 gene product of Xenopus laevis.

Irreversible trapping of DNA during crossed-field gel electrophoresis.

Using an original protocol with a rotating gel electrophoresis apparatus, it is shown that duplex DNA undergoing crossed-field electrophoresis in agarose gets trapped in the gel when the field is increased above a threshold value which decreases with the chain length and depends on the angle between the fields in a non-monotonous manner. This trapping is irreversible, i.e.

Transcriptional organization of the S10, spc and alpha operons of Escherichia coli.

We have investigated the transcription patterns at the inter-operon regions between the S10 and spc, and spc and alpha ribosomal protein operons of Escherichia coli. Newly synthesized transcripts were characterized by RNase T1 protection experiments, and accumulated transcripts were mapped with S1 nuclease. With both techniques we found that about 75% of the RNA polymerases transcribing the S10 operon terminated at the position of a typical rho-independent terminator.

Analysis of chromosomal DNA patterns of the genus Kluyveromyces.

Using an improved procedure of pulsed field gel electrophoresis, yeast chromosomes were separated over a wide range of molecular size (250-4000 kbp) on single gels. The chromosomal DNA patterns of all the species belonging to the genus Kluyveromyces were examined. Within the species K.

Retroregulation of the synthesis of ribosomal proteins L14 and L24 by feedback repressor S8 in Escherichia coli.

Previous studies on regulation of the spc operon containing genes for ribosomal proteins have shown that S8, encoded by the fifth gene of the operon in Escherichia coli, is a translational repressor and regulates the synthesis of the third gene product (L5) and distal gene products by acting at a site near the L5 mRNA translation initiation site. We have now shown that S8 also regulates the synthesis of the first and second gene products (L14 and L24) of the operon by acting at the same mRNA target site--that is, the site located distal to sites coding for L14 and L24--and that mRNA degradation is involved in this retroregulation. It was shown that single base substitutions in the target site, which abolish repression of the synthesis of L5 and L5-distal gene products by S8, also cause derepression of L14-L24 synthesis.

A computer program allows the separation of a wide range of chromosome sizes by pulsed field gel electrophoresis.

The introduction of Pulsed Field Gel Electrophoresis techniques, which allow the separation of DNA molecules of molecular weights as high as chromosomes of lower eukaryotes, has given a powerful tool to geneticists. The resolution expected from these techniques is dependent on numerous parameters, among them pulse time and field strength. A given set of these parameters allows only a limited range of molecular weights to be resolved.

Cloning and DNA sequence determination of the L11 ribosomal protein operon of Serratia marcescens and Proteus vulgaris: translational feedback regulation of the Escherichia coli L11 operon by heterologous L1 proteins.

In Escherichia coli the genes encoding ribosomal proteins L11 (rplK) and L1 (rplA) are contained in a single operon and their expression is translationally regulated by L1. We have cloned the homologous genes from two other enterobacteria, Serratia marcescens and Proteus vulgaris, and determined nucleotide sequences. The genes are organized in a similar way to that found in E.

Mutational alterations of translational coupling in the L11 ribosomal protein operon of Escherichia coli.

The L11 operon in Escherichia coli consists of the genes coding for ribosomal proteins L11 and L1. It is known that translation of L1 does not take place unless the preceding L11 cistron is translated, that is, the two cistrons are translationally coupled, and this is the basis of coregulation of the translation of the two cistrons by a single repressor, L1. Several mutational analyses were carried out to define the region responsible for coupling L1 translation with L11 translation.