Transcription control elements (DNA sequences) are binding sites for transcription factors, proteins that regulate transcription from an associated promoter. Activators stimulate transcription. Repressors inhibit transcription.

AATTGGGGCGGGGC CCCCGCCCCGTTAA ( ) n Hybridize and ligate AATTGGGGCGGGGCAATTGGGGCGGGGCAATTGGGGCGGGGC…………………… CCCCGCCCCGTTAACCCCGCCCCGTTAACCCCGCCCCG…………………… AATTGGGGCGGGGCAATTGGGGCGGGGCAATTGGGGCGGGGC…………………… CCCCGCCCCGTTAACCCCGCCCCGTTAACCCCGCCCCG…………………… Specific sequence DNA affinity column Covalently link synthetic, Ligated DNA to a solid support

Obtain amino acid sequence from isolated transcription factor. Search the cDNA (EST) data base for a cDNA that encodes the transcription factor. Insert this into an expression vector. Assay the ability of the transfected expression vector to stimulate reporter gene expression from a co-transfected reporter plasmid.

WT or mutant Gal4 Gal4 s WT or mutant Gal4 Expression vector:

Fig

E. coli LexA yeast Gal4 aa C N E. coli LexA C N Expression vector for: or LexA binding sites :

Gal4 reporter LexA reporter LexA vector  galactosidase units LexA-Gal4( ) vector + _ _ _ _ _ _ _ _ _

Fig

Fig. 4-17

Fig

Interface of 434 repressor with operator DNA (lower monomer and dimer Interface)

Fig. 3-6

Fig. 2-13

Sequences of C 2 H 2 zinc-fingers in TFIIIA

Fig Zinc-finger protein (C 2 H 2 type)