Abstract
Reversion of haploid, His4- yeast containing a stem-loop mutation in the 5' UTR that blocks HIS4 translation initiation identified four unlinked suppressor genes, SSL1-SSL4, which restore His4+ expression. The SSL2 gene encodes an essential 95 kd protein with ATP-dependent helicase motifs. SSL2 protein is 54% identical to the protein encoded by the human gene, ERCC-3, for which a defective form causes xeroderma pigmentosum and Cockayne's syndrome. An SSL2 allele made to resemble the defective ERCC-3 gene confers UV light hypersensitivity to yeast cells. Hence, SSL2 is the functional homolog of ERCC-3. However, the SSL2 suppressor gene does not restore HIS4 expression by removal of the stem-loop from DNA or the mRNA. We propose that SSL2 and ERCC-3 may have two functions, one defined by a UV repair defect, and a second essential function that is related to gene expression.
Publication types
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Comparative Study
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Base Sequence
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DNA Helicases / genetics*
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DNA Mutational Analysis
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DNA Repair*
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DNA, Fungal / genetics
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Fungal Proteins / genetics*
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Genes, Fungal*
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Genes, Suppressor
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Humans
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Hydrogen Bonding
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Molecular Sequence Data
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Oligodeoxyribonucleotides / chemistry
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Protein Biosynthesis*
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RNA, Messenger / ultrastructure
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Saccharomyces cerevisiae / genetics*
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Saccharomyces cerevisiae Proteins*
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Sequence Alignment
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Transcription Factor TFIIH
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Ultraviolet Rays
Substances
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DNA, Fungal
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Fungal Proteins
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Oligodeoxyribonucleotides
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RNA, Messenger
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SSL2 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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Transcription Factor TFIIH
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DNA Helicases
Associated data
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GENBANK/M84120
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GENBANK/M84163
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GENBANK/M84182
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GENBANK/M94176
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GENBANK/S72766
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GENBANK/S72767
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GENBANK/S72768
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GENBANK/S72769
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GENBANK/S72771
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GENBANK/X63098