Steriod recetor regulatory protein is: (PGI Dec 2006)

Ans: A (Zinc finger ) Three motifs mediate the binding of regulatory proteins to DNA. These are : helix- turn-helix, zinc finger & leucine zipper.Examples of transcription regulatory proteins that contain these motifsBinding MotifOrganismRegulatory ProteinHelix-turn-hetixE colilap repressor CAP Phagel cl, cno, and tryptophan and 434 repressors Mammalshomeo box proteins Pit-1, Oct l, Oct2Zinc fingerE coliGene 32 protein YeastGal4 DrosophillaSerendipity, Hunchback XenopusTFIIIA MammaisSteroid receptorQ family, Sn1Leucine zipperYeastGCN4 MammalsC/EBP, fos, jun, Fca-1, CRE binding protein, c-myc, n-myc, l-myc