molecular midterm 2 cis,trans,tata stuff

cis-acting elements

regulate the transcription of nearby genes; located on the same DNA molecule as the gene they control

ex of cis-acting element

TATA box, enhancers, silencers, operators

trans-acting elements

proteins that regulate gene expression by binding to cis-regulatory elements; encoded by genes on different chromosomes or distant locations from the genes they regulate.

ex of trans-acting element

TFs, activator and repressor proteins, RNA poly and cofactors

promoter region

carries cis-acting elements and instructions to tell the cell when, how, and where a gene will be expressed

TATA binding box

binding site for TFIID which contains TATA-binding protein (TBP); Helps position RNA polymerase II at the correct transcription start site.

enhancers

cis elements that can increase transcription and can be located far upstream or downstream from the transcription start site or even within introns

silencers

cis-acting elements that can decrease transcription and are often located far from the promoter region, inhibiting gene expression.

transcription factors

proteins that bind to cis elements to regulate gene expression

Transcription factors can be _____ (enhance transcription) or _____ (inhibit transcription)

activators, repressors

two major classes of transcription factors:

basal (general) transcription factors and gene-specific transcription factors

basal transcription factors

Proteins present in all eukaryotic cells, that bind to promoters and help initiate transcription.

gene-specific transcription factors

regulate gene very specifically; right time, right cell, right stage

Combinatorial control

regulation of genes by multiple transcription factors acting together

Promoter consensus sequences

short DNA sequences that are recognized by transcription factors and RNA polymerase

BRE (B recognition element)

located immediately upstream of the TATA box and binds to TFIIB

_____ transcription factors are needed for all class II genes

basal

gene regulation often involves sites ______ from promoter

very far