Molecular bio week 2 Flashcards
Do all cells have the same genome, transcriptome and proteome?
Genome same, transcriptome and proteome different
housekeeping genes
genes for maintenance of basic cellular function
specialized genes
genes that make neurons, muscle cells
Finely tunes gene
very tightly regulated genes
Levels of gene regulation
- transcriptional control
- RNA processing control
- RNA transport and localization control
- translation control
- mRNA degradation control
- protein activity control
Heterochromatin
tightly packed version of chromatin, not transcriptionally active
Euchromatin
looser chromatin, more transcriptionally active
Nucleosome
comprised of DNA wrapped around histone proteins
What attaches to mitotic spindle during mitosis?
centromere
Why is chromatin structure dynamic?
chromatin structure is dynamic so it can be accessed
How is dynamic different from conserved?
Dynamic is different from conserved in that the structure is always changing whereas the sequence is conserved
HAT
adds acetyl groups, make more transcriptionally active
HDAC
removes acetyl groups, represses transcription
What determines which DNA strand is used for transcription?
Promoter determines which strand is used
RNA pol I
transcribes ribosomal RNA genes
RNA pol II
transcribes protein-coding (mRNA) and snRNA genes
RNA pol III
transcribes tRNA and other short genes
alpha-amantin
strongly inhibits RNA pol II
actinomycin D
anticancer drug that inhibits RNA Pol II
Rifampin
inhibits mitrochondrial RNA
TFIID - TBP
recognizes TATA box
TFIID - TAF
regulates DNA binding by TBP
recognizes other DNA sequences near the transcription start pt
TFIIB
recognizes BRE element in promoters
positions RNA pol at start site of transcription
TFIIF
stabilizes RNA pol interaction with TBP and TFIIB
TFIIE
attract and regulates TFIIH
TFIIH
unwinds DNA at the transcription start point, phosphorylates Ser5 of the RNA polymerase CTD (carboxy terminal domain) releases RNA pol from promoter
Promoter
sequence that surrounds the TATA box that attracts the RNA pol and initiates transcription
enhancer
short region of DNA that can be bound with protein (activators) to activate transcription of gene or genes
can be about several Kb away from start site
UsnRNP
involved in splicesome complex
cryptic splice site
a site whose sequence resembles an authentic splice site and which might be selected instead of the authentic site during aberrant splicing
SR proteins
serine/arginine proteins involved in selecting splice sites
Poly A binding protein
PABP binds to the tail and interacts with the 5’ cap complex by making a circular mRNA
What are the 2 components of a genetic switch
transcriptional activators that turn on gene expression
transcriptional repressors that turn off gene expression
DNA binding domain
binds to enhancers (allows the factor to sit near specific promoter) This ensures that transcription will be activated from this promoter and not from other promoters
Dimerization domain
these are protein protein interaction domains
Eukaryotic promoters generally require joint action of multiple factors that often interact with one another via these domains.
these domains can allow dimerization of identical or non-identical subunits
Activation domain
domain that “shakes hands” (activates) with the RNA pol
