BIOL 1000 Lecture Notes - Lecture 25: Histone Acetyltransferase, Tata Box, Repressor
Document Summary
Gene expression: definitions, gene: a sequence of nucleotides that codes for one or more biological product (proteins, rna, etc. , genome: the compete genetic information of an organism, gene expression: involves the synthesis of the biological product. Initiation: histone acetyltransferases (hats) acetylate histone proteins to neutralize their positive charges and separate them from the negatively charged dna. Activator proteins bind to enhancer regions located away from the promoter region. Then, the mediator proteins bind to the activators and the promoter region. This enzyme catalyzes the addition of rna bases in the 5" to 3" direction. No primer is required for rna polymerization: at the 5" end, a guanine cap is added to protect the pre-mrna from enzymes in the nucleus, termination. In eukaryotes, the rna polymerase will reach and transcribe a polyadenylation sequence. Once this occurs, the pre-mrna is released from the polymerase. In bacteria, transcription is terminated when the termination sequence is reached.
