Abstract
TBP as a central component in transcriptional regulation can form complexes with various regulatory factors. Using histidine-tagged TBP for affinity-purification of TBP-bound proteins, we isolated a 49-kD protein termed TBP-interacting protein 49 (TIP49) from rat liver nuclear extracts. We cloned the entire cDNA of TIP49 encoding a novel polypeptide of 456 amino acids, and thereafter established an FM3A cell line that constitutively expressed an epitope-tagged TBP. Immunoprecipitation analysis of the cell extracts indicated that TIP49 and TBP were present in an identical complex. Interestingly, the amino acid sequence of TIP49 exhibited high similarity to those sequences of the RuvB bacterial recombination factors which direct branch migration of the Holliday junction and contain the Walker A and B motifs responsible for ATP binding and ATP hydrolysis. These findings suggest that TIP49 is a putative ATP-dependent DNA helicase.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATPases Associated with Diverse Cellular Activities
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Amino Acid Sequence
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Animals
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Bacterial Proteins / chemistry
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Base Sequence
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Blotting, Western
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Carrier Proteins / chemistry*
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Carrier Proteins / genetics
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Carrier Proteins / isolation & purification
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Carrier Proteins / metabolism
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Cell Line
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Cloning, Molecular
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DNA Helicases*
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DNA-Binding Proteins / metabolism*
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Electrophoresis, Polyacrylamide Gel
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Escherichia coli / genetics
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Histidine / metabolism
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Liver / chemistry
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Molecular Sequence Data
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Nuclear Proteins / chemistry*
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Nuclear Proteins / genetics
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Nuclear Proteins / isolation & purification
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Nuclear Proteins / metabolism
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Rats
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Recombinant Proteins / chemistry
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Recombinant Proteins / isolation & purification
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Sequence Homology, Amino Acid
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TATA Box
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TATA-Box Binding Protein
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Transcription Factors / metabolism*
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Transcription, Genetic
Substances
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Bacterial Proteins
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Carrier Proteins
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DNA-Binding Proteins
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Nuclear Proteins
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Recombinant Proteins
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RuvB protein, Bacteria
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TATA-Box Binding Protein
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Transcription Factors
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Histidine
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ATPases Associated with Diverse Cellular Activities
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DNA Helicases
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Ruvbl1 protein, rat