Regulation of gene expression Flashcards
describe gene nomenclature
-all leters in a gene name are italicized
- human gene names are all capitalized
-mouse gene names are only first letter capitalized
what are some gene specific requirements
-intracellular hormone receptor complexes (steroids)
- intracellular second messengers (peptide hormones)
- gene specific transcription factors
- gene regulatory sequences
what is a helix loop helix
common in transcription factors and consists of alpha helices bound by a looping stretch of amino acids
what are DNA binding zinc finger motifs
multiple types, but all have a bound zinc metal ion associated with the protein. some have an alpha helix plus beta sheet structure, others have a more helix-turn-helix sstructural motif
- generally binds over larger stretch of DNA
what are helix turn helix
DNA binding motif with 2 alpha helices form a Y shaped coiled coil structure, results in both protein and DNA bindinf
what do the majority of DNA binding proteins function as
dimers or tandem clusters
what does the leucine zipper do
promotes both DNA binding and dimerization
in prokaryotes where is the start of transcipriton in relation to the location of the control sequences
the repressor and activator binding sites are generally closely juxtaposed to the RNA polymerase binding site
in eukaryotes where is the start of transcription in relation to the location of the control sequences
DNA regulatory sequences can be located at great distances relative to the start site of transcription, be found in the 5’ to 3’ flanking regions and in introns
where is the TATA box located and what does it bind
~25-30 BP 5’ of the start site of transcription and binds TBP subunit of TFIID
what does the INR contain and what does it bind
start site of transcription for many RNA pol II genes and binds TFIID
where is DPE located and what does it bind
located at +30 3’ of the start site and binds TFIID
where is BRE located and what does it bind
located at -35 5’ of the start site and binds TFIIB
what are the steps of activatino of transcription at a specific promotor
gene activator protein binds to chromatin -> chromatin remodeling -> covalent histone modification -> addition activator proteins bound to gene regulatory proteins -> assembly of pre-initiation complex at the promoter -> transcription initiation
what controls the mRNA in the cytosol
microRNA
