Molecular Genetics: Transcription Flashcards
RNA polymerases
synthesize RNA from 5’ to 3’ without a primer
sigma
protein in prokaryotes that binds to RNA polymerase and promoter regulatory sequences
holoenzyme
sigma, DNA, RNA polymerase complex
different sigmas for
regulation of gene expression for different stress responses
-10 box and -35 box
areas in the promoter region in prokaryotes to determine direction of transciption
rudder
structure in RNA polymerase that guides template and coding strands to appropriate channels
zipper
structure in RNA polymerase that separates RNA from DNA template
termination signal
self-complementary RNA sequence that forms a hairpin loop to allow RNA to dissociate from DNA
transcription start site (+1)
upstream of protein-coding genes
5’ UTR and 3’ UTR
stabilize mRNA and involved in translation regulation
RNA polymerase II
in eukaryotes transcribes protein encoding genes
RNA polymerase I
in eukaryotes synthesizes ribosomal RNAs
RNA polymerase III
in eukaryoes synthesizes tRNA and small regulatory RNAs
RNA polymerases IV and V
plant specific and regulatory RNAs
basal transcription factor
proteins absolutely necessary for transcription to happen (sigma in prokaryotes, TATA binding protein in eukaryotes)
-30 position in eukaryotes
TATA box
in eukaryotes transcription ends when
polyA signal is transcribed
primary transcript/ pre-mRNA
initial product of transcription in eukaryotes
RNA splicing
removing introns and joining exons together
small nuclear RNAs (snRNPs)
catalyze RNA splicing
spliceosome
snRNPs bound to RNA - intron guided into a self-complementary loop which is cleaved
isoforms
different ways primary RNAs can be spliced to create a different version of a protein
5’ cap
modified guanine and triphosphate
polyA tail
added to the 3’ end by polyadenylate polymerase
what to the 5’ cap and polyA tail do?
proteins bind to them to help facilitate mRNA exit from the nucleus and prevent degradation and function in translation initiation
