Purification of a novel 55 kDa HeLa cell nuclear DNA-binding protein.
A novel 55 kDa DNA-binding protein (p55) was purified from HeLa cell nuclear extracts to apparent homogeneity by conventional chromatography coupled with DNA-affinity chromatography. The DNA-binding activity of p55, followed by band mobility shift and Southwestern assays, was enriched 800-fold. This relatively abundant protein was shown to bind nonspecifically to DNA. When added to nuclear extracts, p55 enhanced 2-fold the in vitro transcription of CAT reporter gene driven by the SV40 promoter. The sequence of the N-terminal 20 amino acid residues of purified p55 was determined as APSTPLLTV(P)G(S)EGLYMVNG, homologies could be found when compared to protein sequences available in all databanks.
Zhang
W W
WW
Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030.
Farrés
J
J
Busch
H
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004268:DNA-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000302:isolation & purification* / Q000378:metabolism; D010446:Peptide Fragments / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments