scholarly journals The HAP3 regulatory locus of Saccharomyces cerevisiae encodes divergent overlapping transcripts.

1988 ◽  
Vol 8 (2) ◽  
pp. 655-663 ◽  
Author(s):  
S Hahn ◽  
J Pinkham ◽  
R Wei ◽  
R Miller ◽  
L Guarente

Activation of the CYC1 upstream activation site, UAS2, and transcription of several other genes encoding respiratory functions requires the product of the regulatory gene HAP2. We report here the isolation and characterization of a second UAS2 regulatory gene, HAP3. Like mutations in HAP2, a mutation in HAP3 abolishes the activity of UAS2 and prevents growth on nonfermentable carbon sources. The HAP3 gene was cloned and, surprisingly, was found to encode two divergently transcribed, overlapping transcripts: a 570-base RNA and a 3-kilobase (kb) RNA. Chromosomal disruption experiments defined the critical region for HAP3 function to a 1.3-kb segment in which the two transcripts overlap. Analysis of the HAP3 DNA sequence showed that the 570-base transcript could encode a protein of 144 amino acids. Synthesis of the 144-amino-acid protein under regulatory control in vivo demonstrated that this protein is essential for activity of UAS2 as well as for growth on nonfermentable carbon sources. The largest open reading frame in the critical region of the 3-kb transcript is only 86 amino acids. Using site-directed mutagenesis, we demonstrated that the 86-amino-acid open reading frame was not involved in UAS2 activity. The possible role of this 3-kb antisense RNA in HAP3 expression or function is discussed.

1988 ◽  
Vol 8 (2) ◽  
pp. 655-663
Author(s):  
S Hahn ◽  
J Pinkham ◽  
R Wei ◽  
R Miller ◽  
L Guarente

Activation of the CYC1 upstream activation site, UAS2, and transcription of several other genes encoding respiratory functions requires the product of the regulatory gene HAP2. We report here the isolation and characterization of a second UAS2 regulatory gene, HAP3. Like mutations in HAP2, a mutation in HAP3 abolishes the activity of UAS2 and prevents growth on nonfermentable carbon sources. The HAP3 gene was cloned and, surprisingly, was found to encode two divergently transcribed, overlapping transcripts: a 570-base RNA and a 3-kilobase (kb) RNA. Chromosomal disruption experiments defined the critical region for HAP3 function to a 1.3-kb segment in which the two transcripts overlap. Analysis of the HAP3 DNA sequence showed that the 570-base transcript could encode a protein of 144 amino acids. Synthesis of the 144-amino-acid protein under regulatory control in vivo demonstrated that this protein is essential for activity of UAS2 as well as for growth on nonfermentable carbon sources. The largest open reading frame in the critical region of the 3-kb transcript is only 86 amino acids. Using site-directed mutagenesis, we demonstrated that the 86-amino-acid open reading frame was not involved in UAS2 activity. The possible role of this 3-kb antisense RNA in HAP3 expression or function is discussed.


Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 644-651 ◽  
Author(s):  
Kenneth Koo ◽  
W. Dorsey Stuart

The gene product of the mtr locus of Neurospora crassa is required for the transport of neutral aliphatic and aromatic amino acids via the N system. We have previously cloned three cosmids containing Neurospora DNA that complement the mtr-6(r) mutant allele. The cloned DNAs were tightly linked to restriction fragment length polymorphisms that flank the mtr locus. A 2.9-kbp fragment from one cosmid was subcloned and found to complement the mtr-6(r) allele. Here we report the sequence of the fragment that hybridized to a poly(A)+ mRNA transcript of about 2300 nucleotides. We have identified an 845-bp open reading frame (ORF) having a 59-bp intron as the potential mtr ORF. S1 nuclease analysis of the transcript confirmed the transcript size and the presence of the intron. A second open reading frame was found upstream in the same reading frame as the mtr ORF and appears to be present in the mRNA transcript. The mtr ORF is predicted to encode a 261 amino acid polypeptide with a molecular mass of 28 613 Da. The proposed polypeptide exhibits six potential α-helical transmembrane domains with an average length of 23 amino acids, does not have a signal sequence, and contains amino acid sequence homologous to an RNA binding motif.Key words: sequence, membranes, ribonucleoprotein.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


1998 ◽  
Vol 42 (2) ◽  
pp. 436-439 ◽  
Author(s):  
T. R. Walsh ◽  
W. A. Neville ◽  
M. H. Haran ◽  
D. Tolson ◽  
D. J. Payne ◽  
...  

ABSTRACT The Aeromonas veronii bv. sobria metallo-β-lactamase gene, imiS, was cloned. The imiS open reading frame extends for 762 bp and encodes a protein of 254 amino acids with a secreted modified protein of 227 amino acids and a predicted pI of 8.1. To confirm the predicted sequence, purified ImiS was digested and the resulting peptides were identified, yielding an identical sequence for ImiS, with 98% identity to CphA. Both possessed the putative active-site sequence Asn-Tyr-His-Thr-Asp at positions 88 to 92, which is unique to the Aeromonas metallo-β-lactamases.


Genetics ◽  
1987 ◽  
Vol 116 (1) ◽  
pp. 67-73
Author(s):  
Tim P Keith ◽  
Margaret A Riley ◽  
Martin Kreitman ◽  
R C Lewontin ◽  
Daniel Curtis ◽  
...  

ABSTRACT We determined the nucleotide sequence of a 4.6-kb Eco RI fragment containing 70% of the rosy locus. In combination with information on the 5′ sequence, the gene has been sequenced in entirety. rosy cDNAs have been isolated and intron/exon boundaries have been determined. We find an open reading frame which spans four exons and would encode a protein of 1335 amino acids. The molecular weight of the encoded protein (xanthine dehydrogenase), based on the amino acid translation, is 146,898 daltons which agrees well with earlier biophysical estimates. Characteristics of the protein are discussed.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721 ◽  
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


1989 ◽  
Vol 9 (7) ◽  
pp. 2989-2999 ◽  
Author(s):  
H M Traglia ◽  
N S Atkinson ◽  
A K Hopper

The yeast gene RNA1 has been defined by the thermosensitive rna1-1 lesion. This lesion interferes with the processing and production of all major classes of RNA. Each class of RNA is affected at a distinct and presumably unrelated step. Furthermore, RNA does not appear to exit the nucleus. To investigate how the RNA1 gene product can pleiotropically affect disparate processes, we undertook a structural analysis of wild-type and mutant RNA1 genes. The wild-type gene was found to contain a 407-amino-acid open reading frame that encodes a hydrophilic protein. No clue regarding the function of the RNA1 protein was obtained by searching banks for similarity to other known gene products. Surprisingly, the rna1-1 lesion was found to code for two amino acid differences from wild type. We found that neither single-amino-acid change alone resulted in temperature sensitivity. The carboxy-terminal region of the RNA1 open reading frame contains a highly acidic domain extending from amino acids 334 to 400. We generated genomic deletions that removed C-terminal regions of this protein. Deletion of amino acids 397 to 407 did not appear to affect cell growth. Removal of amino acids 359 to 397, a region containing 24 acidic residues, caused temperature-sensitive growth. This allele, rna1-delta 359-397, defines a second conditional lesion of the RNA1 locus. We found that strains possessing the rna1-delta 359-397 allele did not show thermosensitive defects in pre-rRNA or pre-tRNA processing. Removal of amino acids 330 to 407 resulted in loss of viability.


1987 ◽  
Vol 7 (8) ◽  
pp. 2728-2734 ◽  
Author(s):  
C A Strick ◽  
T D Fox

The yeast nuclear gene PET111 is required specifically for translation of the mitochondrion-coded mRNA for cytochrome c oxidase subunit II. We have determined the nucleotide sequence of a 3-kilobase segment of DNA that carries PET111. The sequence contains a single long open reading frame that predicts a basic protein of 718 amino acids. The PET111 gene product is a mitochondrial protein, since a hybrid protein which includes the amino-terminal 154 amino acids of PET111 fused to beta-galactosidase is specifically associated with mitochondria. PET111 is translated from a 2.9-kilobase mRNA which, interestingly, has an extended 5'-leader sequence containing four short open reading frames upstream of the long open reading frame. These open reading frames exhibit an interesting pattern of overlap with each other and with the PET111 reading frame.


1986 ◽  
Vol 6 (1) ◽  
pp. 265-276
Author(s):  
C Upton ◽  
G McFadden

DNA hybridization experiments indicate that the genome of a tumorigenic poxvirus. Shope fibroma virus (SFV), possesses sequence homology with DNA isolated from uninfected rabbit cells. Southern blotting experiments, either with high-complexity rabbit DNA as probe and SFV restriction fragments as targets or with high-specific activity, 32P-labeled, cloned SFV sequences as probes and rabbit DNA as target, indicate that the homologous sequences map at two locations within the viral genome, one in each copy of the terminal inverted repeat sequences. Unexpectedly, Southern blots revealed that the homologous host sequences reside in a rabbit extrachromosomal DNA element. This autonomous low-molecular-weight DNA species could be specifically amplified by cycloheximide treatment and was shown by isopycnic centrifugation in cesium chloride-ethidium bromide to consist predominantly of covalently closed circular DNA molecules. DNA sequencing of pSIC-9, a cloned 1.9-kilobase fragment of the rabbit plasmid species, indicated extensive homology at the nucleotide level over a 1.5-kilobase stretch of the viral terminal inverted repeat. Analysis of open reading frames in both the plasmid and SFV DNA revealed that (i) the N-terminal 157-amino acid sequence of a potential 514-amino acid SFV polypeptide is identical to the N-terminal 157 amino acids of one pSIC-9 open reading frame, and (ii) a second long pSIC-9 open reading frame of 361 amino acids, although significantly diverged from the comparable nucleotide sequence in the virus, possessed considerable homology to a family of cellular protease inhibitors, including alpha 1-antichymotrypsin, alpha 1-antitrypsin, and antithrombin III. The potential role of such cellular plasmid-like DNA species as a mediator in the exchange of genetic information between the host cell and a cytoplasmically replicating poxvirus is discussed.


1987 ◽  
Vol 7 (8) ◽  
pp. 2728-2734
Author(s):  
C A Strick ◽  
T D Fox

The yeast nuclear gene PET111 is required specifically for translation of the mitochondrion-coded mRNA for cytochrome c oxidase subunit II. We have determined the nucleotide sequence of a 3-kilobase segment of DNA that carries PET111. The sequence contains a single long open reading frame that predicts a basic protein of 718 amino acids. The PET111 gene product is a mitochondrial protein, since a hybrid protein which includes the amino-terminal 154 amino acids of PET111 fused to beta-galactosidase is specifically associated with mitochondria. PET111 is translated from a 2.9-kilobase mRNA which, interestingly, has an extended 5'-leader sequence containing four short open reading frames upstream of the long open reading frame. These open reading frames exhibit an interesting pattern of overlap with each other and with the PET111 reading frame.


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