The complete sequence of a chicken‐muscle cDNA encoding the acidic ribosomal protein P1

Abstract
The developmentally regulated 5''-flanking DNase-I-hypersensitive site of the chicken .beta.H-globin gene in nuclei contains a subregion which is resistant to DNase I and which disappears when nuclei are extracted with 0.3 M NaCl, suggesting that there are salt-extractable proteins bound to sequences within this region. The 0.3 M NaCl extract contains two proteins which bind in vitro to these sequences. One of the binding sequences has an inverted repeat very similar to that bound by TGGCA protein. Partially purified TGGCA protein from chicken liver binds to this sequence in vitro giving exactly the same footprint as that obtained with erythroid nuclear proteins. Similarly TGGCA protein binds to an inverted repeat with the .beta.A-globin 5''-hypersensitive site giving a footprint identical to that obtained with erythroid nuclear protein extracts. From competition footprinting experiments and the electorphoretic mobility of the protein-DNA complex, it is concluded that the erythroid proteins previously described as binding to the .beta.H- and .beta.A-globin inverted repeats within the 5''-flanking hypersensitive sites both belong ot the TGGCA protein family.