BCEM 393 Lecture Notes - Lecture 16: Tata Box, Rifampicin, Dactinomycin
27 Jun 2018
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Prokaryotic Transcription
FLOW OF GENETIC INFORMATION
-Key points:
-Protein “factors” assemble at the beginning of a gene
-The RNA polymerase races along the dsDNA reading the gene
-mRNA uses uracil (U) instead of thymine (T) in transcription
-Substrates: ATP, GTP, CTP, UTP
-RNA unzips dsDNA
-The mRNA goes from the nucleus to the cytoplasm for translation
MRNA, TRNA, RRNA, ETC
-mRNA is the messenger RNA that codes for protein sequences
-tRNA is the transfer RNA, which is used during protein synthesis
-tRNA also brings amino acids into transcriptional machinery
-Reads the codons on mRNA and translates it into amino acids
-rRNA is ribosomal RNA, which is part of the ribosome
-Directs the catalytic steps of protein synthesis
-Amino acids from tRNA are then put together into the right conformation by the ribosome,
to make the protein
RNA POLYMERASE ADDS TO THE
3’ END
-RNA polymerases does not re-
quire a primer to begin adding
nucleotides
-RNA polymerases catalyze the
attack by the 3’—OH on the al-
pha-phosphate of NTP, so the
chain grows longer at the 3’
end
RNA POLYMERASE AND ITS RE-
ACTION
-Substrates are ATP, GTP, UTP, and CTP
-Subunit structure is alpha2betabeta’sigma
-alpha2 helps identify where to start transcription
-The alpha subunits are involved in assembling this complex and in recognizing where to be-
gin transcription
THREE STAGES OF POLYMERIZATION
-Initiation
-Requires a signal
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Protein factors assemble at the beginning of a gene. The rna polymerase races along the dsdna reading the gene. Mrna uses uracil (u) instead of thymine (t) in transcription. The mrna goes from the nucleus to the cytoplasm for translation. Mrna is the messenger rna that codes for protein sequences. Trna is the transfer rna, which is used during protein synthesis. Trna also brings amino acids into transcriptional machinery. Reads the codons on mrna and translates it into amino acids. Rrna is ribosomal rna, which is part of the ribosome. Directs the catalytic steps of protein synthesis. Amino acids from trna are then put together into the right conformation by the ribosome, to make the protein. Rna polymerases does not re- quire a primer to begin adding nucleotides. Rna polymerases catalyze the attack by the 3" oh on the al- pha-phosphate of ntp, so the chain grows longer at the 3" end. Substrates are atp, gtp, utp, and ctp.
