[Major p50 protein of the somatic cell cytoplasmic mRNP: expression in Escherichia coli, isolation, and some properties of the recombinant protein].

The major mRNP protein of rabbit reticulocytes, p50, belonging to the family of Y-box transcription factors has been expressed in E. coli. The isolation procedure of the recombinant protein has been described. The recombinant protein is similar to the protein isolated from rabbit mRNPs in SDS-PAGE mobility and interaction with specific antibodies. Similar to the natural protein, the recombinant protein forms homooligomeric complexes with a molecular mass of about 800 kDa, binds to the alpha-globin RNA and double-stranded DNA containing the Y-box. Both proteins can be phosphorylated in vitro.