Sequence of cDNA comprising the human pur gene and sequence-specific single-stranded-DNA-binding properties of the encoded protein.
The human Pur factor binds strongly to a sequence element repeated within zones of initiation of DNA replication in several eukaryotic cells. The protein binds preferentially to the purine-rich single strand of this element, PUR. We report here the cloning and sequencing of a cDNA encoding a protein with strong affinity for the PUR element. Analysis with a series of mutated oligonucleotides defines a minimal single-stranded DNA Pur-binding element. The expressed Pur open reading frame encodes a protein of 322 amino acids. This protein, Pur alpha, contains three repeats of a consensus motif of 23 amino acids and two repeats of a second consensus motif of 26 amino acids. Near its carboxy terminus, the protein possesses an amphipathic alpha-helix and a glutamine-rich domain. The repeat region of Pur cDNA is homologous to multiple mRNA species in each of several human cell lines and tissues. The HeLa cDNA library also includes a clone encoding a related gene, Pur beta, containing a version of the 23-amino-acid consensus motif similar, but not identical, to those in Pur alpha. Results indicate a novel type of modular protein with capacity to bind repeated elements in single-stranded DNA.
Bergemann
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AD
Department of Pathology, Mount Sinai Medical School, New York, New York 10029.
Ma
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Johnson
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EM
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015723:Gene Library; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009928:Organ Specificity / Q000235:genetics; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C501130:PURA protein, human; D014157:Transcription Factors; D004247:DNA