Translation Intro to operons Flashcards
RNA to protein
Information containing -code for proteins
Energy containing-transports amino acids
Catalytic/enzyme-assembles amino acid
Ribosomes
Consists of RNA +Protein
Bacterial Ribosome:30S +50S=70S
Ribosome=rRNA +Protein
23S rRNA=ribozyme catalyzes peptide bonds
Acceptor=A,Peptide=P,Exit=E
Making charged tRNA
Aminoacyl tRNA synthetase
Enzyme that adds correct amino acid to tRNA-one per amino acid
High energy bond tRNA- AA
Codon-anticodon matching
How to make sure the correct AA is added into polypeptide/protein
Degenerate code: not a one-to-one match-multiple RNA codons-single amino acid
Wobble: one tRNA may bind multiple related codons
Bacterial codons
start codons: UUG-Leu, AUG-Met, GUG-Val
Stop: UAA, UAG,UGA
Shine-Dalgarno sequence
Ribosome binding sequence/site
High purine (AG) sequence
3-10 bases long with GGAGG core
Initiation
30S small subunit,mRNA,fMet-tRNA (if AUG)
requires initiation factors,GTP
30S initiation complex
50S subunit
Elongation
sites in 50S ribosomal subunit
A=Acceptor
P=Peptide
E=Exit
charged tRNA
Termination-Translation
Ribosome reaches stop codon in mRNA: UAA, UAG,UGA
stop codon does not code for amino acids,just release factors
RF-recognize stop codon and binds to A-site
Requires GTP
Inteins
INternal proTEINS
self splice out of exteins
Protein folding
Most proteins self-assemble during translation
some need help
Molecular chaperones=chaperone protein=chapreones=heat shock protein
Powered by ATP
DnaJ (hsp40), DnaK (hsp70)
GroEL,GroES
Sec (secretion) system for export of unfolded proteins
Signal recognition particle (SRP)
For export or membrane
Tat system for export of folded proteins
2 arginines in the signal sequence
less common than Sec
