Production of a truncated human c-myc protein which binds to DNA.
Two kinds of truncated human c-myc proteins were produced in Escherichia coli. The human c-myc gene is composed of three exons, exons 2 and 3 having coding capacity for a protein of 439 amino acids. 252 N-terminal amino acids are encoded by exon 2, the C-terminal 187 amino acids being encoded by exon 3. One of the proteins (p42) produced in E. coli corresponds to 342 amino acids from the 98th Gln to the C-terminus, plus 21 amino acids derived from the H-ras gene at the N-terminus. The other (p23) corresponds to 155 amino acids from the 98th Gln to the 252nd Ser, plus five amino acids (Gly-Gly-Thr-Arg-Arg) at the C-terminus, plus 21 amino acids from the H-ras gene at the N-terminus. The p23 protein was produced by using cDNA in which a frame shift occurred at the boundary between exons 2 and 3. We investigated the DNA-binding activity in p42 and p23 proteins. DNA-cellulose column chromatography showed that p42 binds to DNA, whereas p23 does not. This DNA-binding activity of p42 was inhibited by antiserum prepared against p42 but not by antiserum against p23. This indicates that the DNA-binding activity of c-myc protein is localized in the portion encoded by exon 3.
Naoe
T
T
Institute for Comprehensive Medical Science, Fujita-Gakuen Health University, Aichi, Japan.
Shiku
H
H
Yamada
K
K
Okazaki
T
T
Kurosawa
Y
Y
D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli; D005091:Exons; D006801:Humans; D007158:Immunologic Techniques; D008970:Molecular Weight; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D011994:Recombinant Proteins / Q000378:metabolism
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D011994:Recombinant Proteins