Biomedical subjects

H Sychrova

Publications and source records attributed to H Sychrova.

7 recordsLinked to original sources

PubMed2000

Sequence and organization analyses of a Zygosaccharomyces rouxii DNA fragment containing the HIS3 gene.

The nucleotide sequence of a 3.4 kb fragment containing the HIS3 gene of the osmotolerant yeast Zygosaccharomyces rouxii has been determined. The fragment was cloned from a Z. rouxii genomic DNA library by complementation of a Saccharomyces cerevisiae his3 mutant strain. The sequenced DNA fragment contained three open reading frames; the middle one (678 bp long, predicting a protein of 226 amino acids) shared a high degree of similarity with HIS3 genes of other yeast species. In the promoter region of the putative ZrHIS3 gene, a T(c) element required for constitutive transcription was found. The GenBank Accession No. of the sequenced DNA region is Y18561.

Amino Acid Sequence↗

PubMed2000

Organization of specific genomic regions of Zygosaccharomyces rouxii and Pichia sorbitophila: comparison with Saccharomyces cerevisiae.

The genomes of Zygosaccharomyces rouxii and Pichia sorbitophila were partially explored. The genome of Z. rouxii CBS 732 consists of seven chromosomes with an approximate size of 1.0-2.75 Mb, 12.8 Mb in total. Five of the chromosomes were labelled with specific probes. Three Z. rouxii genomic DNA fragments were sequenced; all 10 ORFs found were without introns and they have homologues in S. cerevisiae. Gene order comparison revealed that the organization is partially conserved in both species. The genome of P. sorbitophila CBS 7064 consists of seven chromosomes with an approximate size of 1.0-2.9 Mb, 13.9 Mb in total. Three of the chromosomes were labelled with specific probes. The sequencing of a 5.2 kb genomic DNA fragment revealed three ORFs, but no conservation of their organization was found, although all of them have their respective homologues in S. cerevisiae. According to our results, the presence of two overlapping ORFs in S. cerevisiae (YJL107c-YJL108c) could be interpreted as the result of a frameshift mutation.

Base Sequence↗

PubMed1999

Molecular cloning and sequence analysis of Zygosaccharomyces rouxii ADE2 gene encoding a phosphoribosyl-aminoimidazole carboxylase.

The nucleotide sequence of a 2.8 kb fragment containing the ADE2 gene of the osmotolerant yeast Zygosaccharomyces rouxii has been determined. The gene was cloned from a Z. rouxii genomic DNA library by complementation of the Saccharomyces cerevisae ade2 mutant strain. The sequenced DNA fragment contains a 1710 bp open reading frame predicting a protein of 570 amino acids. The deduced amino acid sequence shares a high degree of homology with Ade2p homologues in five other yeast species.

Amino Acid Sequence↗

PubMed1996

Characterization of the NHA1 gene encoding a Na+/H+-antiporter of the yeast Saccharomyces cerevisiae.

The NHA1 gene (2958 nt) encoding a putative Na(+)/H(+) antiporter (986 aa) in Saccharomyces cerevisiae was cloned by selection based on increased NaCl tolerance. The putative protein is highly similar to sodium/proton antiporters from Schizosaccharomyces pombe (gene sod2), and Zygosaccharomyces rouxii (gene Z-SOD2). Overexpression of the NHA1 gene results in higher and partially pH-dependent tolerance to sodium and lithium; its disruption leads to an increased sensitivity towards these ions.

Amino Acid Sequence↗

PubMed1994

APL1, a yeast gene encoding a putative permease for basic amino acids.

A Saccharomyces cerevisiae gene (1722 bp), encoding a protein (574 aa) highly homologous to the basic-amino-acid permeases LYP1 and CAN1, was sequenced. The gene, which was named APL1 (Amino-acid Permase Like), is located 881 bp upstream from LYP1 (lysine-specific permease), and in head-to-head orientation to it. These sequence data have been deposited in the EMBL/GenBank/DDBJ nucleotide sequence data libraries under Accession Number X74069.

Amino Acid Sequence↗

PubMed1993

Cloning and sequencing of the Saccharomyces cerevisiae gene LYP1 coding for a lysine-specific permease.

The LYP1 gene of Saccharomyces cerevisiae was cloned by complementation in lysine-permease-deficient recipient yeast cells, and its nucleotide sequence was determined. An open reading frame of 1833 nucleotides was found encoding a polypeptide of 611 amino acids, with a calculated molecular weight of 68 118. Analysis of the deduced primary structure of the protein revealed ten membrane-spanning regions and three potential N-glycosylation sites. Analysis of the deduced sequence of protein LYP1 indicates homology with other yeast amino-acid permeases, in particular with CAN1, and also the lysine-specific permease of Escherichia coli. The strain transformed by a multi-copy plasmid harbouring the LYP1 gene, showed a 20-fold increase in the maximum velocity of lysine uptake over that in the wild type, with no changes in the affinity of the permease for its substrate.

Amino Acid Sequence↗

PubMed1992

Determination of a specific region of the purine-cytosine permease involved in the recognition of its substrates.

Three u.v.-induced mutants of the purine-cytosine permease gene of Saccharomyces cerevisiae, with altered apparent Michaelis constant of transport (Kmapp), were cloned and sequenced. One of the mutants had extensive nucleotide replacement, whereas the other two had a single mutation. To evaluate the contribution of the different amino acid replacements to the phenotype of the complex mutant, simpler mutants were created by site-directed mutagenesis. All the amino acid replacements found in the segment from amino acids 371 to 377 inclusive, contribute to the determination of the phenotype. According to the model postulated this segment lies on the cell surface. In particular, amino acids at position 374 and 377 modulate the affinity of the permease towards its substrates. In the wild-type, when asparagine is present at both of these positions, the lowest Kmapp values are found.

Alleles↗