Xenopus transcription factor A requires zinc for binding to the 5 S RNA gene.
Transcription factor A from immature Xenopus oocytes is found associated with 5 S RNA in a 7 S nucleoprotein complex. Atomic absorption analysis of EDTA-dialyzed 7 S particles reveals 2 mol of zinc/mol of particle. Factor A obtained from EDTA-dialyzed particles binds specifically to the 5 S RNA gene as determined by DNase I footprinting. Factor A alone, obtained by RNase digestion of the 7 S particle, contains zinc when dialyzed in the absence of EDTA. However, the zinc bound to free factor A is removed by dialysis against a buffer containing EDTA. The apoprotein does not bind to the 5 S RNA gene. Inhibition of footprinting is also effected by addition of EDTA to factor A without prolonged dialysis. Under these conditions, specific DNA binding ability is restored following addition of zinc. 1,10-Phenanthroline also inhibits binding of factor A to the intragenic control region of the 5 S RNA gene. In addition, this reagent specifically inhibits factor A-dependent synthesis of 5 S RNA but not factor A-independent tRNA synthesis in a HeLa cell in vitro transcription system.
D000818:Animals; D003850:Deoxyribonuclease I; D004492:Edetic Acid / Q000494:pharmacology; D004706:Endodeoxyribonucleases / Q000378:metabolism; D010618:Phenanthrolines / Q000494:pharmacology; D012313:RNA / Q000235:genetics*; D012260:Ribonucleases / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014982:Xenopus laevis; D015032:Zinc / Q000378:metabolism*
D010618:Phenanthrolines; D014157:Transcription Factors; D012313:RNA; D004492:Edetic Acid; D004706:Endodeoxyribonucleases; D012260:Ribonucleases; D003850:Deoxyribonuclease I; D015032:Zinc; C025205:1,10-phenanthroline