1. TRANSLATION IN PROKARYOTES
By:
MARYAM SHAKEEL

2. The process in which the
messenger
RNA
(mRNA)
generated by transcription is
interpreted by the ribosome to
generate a particular amino acid
succession, or polypeptide that
will fold into an active protein.

3. Bringing the Small Ribosomal Subunit to the Initiation
Codon
 Binding of small ribosomal subunit to the initiation
codon at m-RNA.
 How small subunit of ribosomes select initiation
codon
Shine-Dalgarno
Sequence
Initiation factors
 IF1,IF2,IF3

5. Bringing the first aa-tRNA into the
ribosome
 AUG is an initiation and only one
codon for METHIONINE.
It is always first
amino acid in
polypeptide chain
t-RNA enter at P site and bind to
both AUG & IF2
Assemble complete Initiation
complex
 Larger subunit join complex
 GTP hydrolyse
 IF2-GDP release


6. Series of steps is repeated
over and over as amino
acids are polymerised in
growing polypeptide chain
Aminoacyl-t RNA Selection
 Entry of second aminoacyltRNA in A site
Must join EF-Tu
bound to GTP
 EF-Tu is
require to deliver aminoacyltRNA to A site
 Complex of aminoacyltRNA
Tu-GTP enter
 GTP is hydrolyse and TuGTP release

7. Peptide Bond Formation
 Two amino acid, attached with separate tRNA are
juxtaposed in such position that the can react

Amine nitrogen of the aatRNA in A site carries out a
nucleophilic attack on
carbonyl carbon of amino
acid bound to tRNA of P site

8. A component of large ribosomal
subunit known as ribozyme.

9. TRANSLOCATION
 It is actually characterized by a
ratchet-like motion of
ribosomes
Ribosomes moves
three nucleotide along
mRNA in 5’-3’ direction


Dipeptidyl-tRNA shift from A
site P site
GTP hydrolyse and EF-GGDP leaves

10. Releasing the Deacylated
tRNA


Deacylated tRNA leaves
ribosome
Empty E site

11. 
STOP CODON
Release Factor


Class 1 RFs
RF1, RF2
Class 2 RFs
GTP binding protein