Purification and characterization of ATBP, a novel protein that binds to A/T stretches in three segments of the Sarcophaga lectin gene.
A DNA-binding protein for the Sarcophaga lectin gene, ATBP (A/T-stretches-binding protein) was purified to homogeneity from the nuclear extract of NIH-Sape-4 cells. The molecular mass of ATBP determined under denaturing conditions was 53 kDa, but its native molecular mass estimated by gel-filtration chromatography was 430 kDa, suggesting that it is an octamer of the 53-kDa subunit. This protein bound to at least three DNA fragments from the Sarcophaga lectin gene, two of them are in the 5'-upstream region and the other is in a region containing an intron. These fragments are very AT rich and inlaid with stretches of A or T residues (A/T stretches). ATBP was found to have affinity for poly[d(A-T)]. These results suggest that ATBP binds to A/T stretches in the three DNA fragments from this gene. Furthermore, longer DNA was found to be bound more effectively, suggesting that an octamer of the 53-kDa subunit has multiple binding sites for the DNA fragments and requires a relatively long DNA sequence for binding.
Matsui
M
M
Faculty of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Japan.
Kobayashi
A
A
Kubo
T
T
Natori
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000302:isolation & purification / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004175:Diptera / Q000235:genetics* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D019476:Insect Proteins; D007438:Introns; D007700:Kinetics; D037102:Lectins / Q000235:genetics*; D037181:Lectins, C-Type; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011067:Poly dA-dT / Q000378:metabolism; D016133:Polymerase Chain Reaction; D016385:TATA Box
C043030:20kDa lectin protein, Sarcophaga; D004268:DNA-Binding Proteins; D019476:Insect Proteins; D037102:Lectins; D037181:Lectins, C-Type; D011067:Poly dA-dT; D004247:DNA