Translation process: Initiation (step by step overview )

we know by the translation process we get protein from mRNA that was previously produced from DNA by the process of transcription. Translation process need some steps and enzymes to complete the action and two ribosomal subunit . steps are:
1.Initiation
2.Elongation
3.Termination

Lets see the overview......

Initiation:

Two ribosomal subunits are separated by the two initiation factor IF1 and IF3 now this small subunit with this two factors bind with the shine dalgarno sequence of the upstream region of the mRNA.Shine dalgarno sequence is the ribosomal binding site of prokaryotes situated in the upstream of the start codom AUG. Here in the figure you mark the mRNA as 5'-3' as I forgot.

Shine Dalgarno sequence is the ribosomal binding site of prokaryotes situated in the upstream of the start codon AUG.By the shine Dalgarno sequece the small ribosomal subunit attach with this mRNA and this initiate the translation by combining with the mRNA with the small ribosomal subunit.

In the mRNA you see the start and stop codon, AUG is the start codon from where translation initiated and UAA/UGA/UAG are the stop codon that terminate the translation process.

Now another initiation factor IF2  brings with initiator tRNA charged with f-met (Formylated methionine) will come and bind with the small ribosomal subunit. IF2 need energy to run the tRNA for that reason it is contain  energy souce GTP. f met will bind with the complementary sequence of the start codon of mRNA.

Now its time to come large ribosomal subunit come and bind with the small ribosomal subunit  ,and GTP is now will converted into GDP and all the initiation factors will be released ,

as all of the factors released now small ( 30 S) and Large ( 50 S) both subunits make a close complex called 70 S ribosomal subunit. that is the total view of initiation of translation cause now the mRNA is totally ready to produce protein.

Protein production process done in elongation process by making amino acid bonds and finally terminated in termination. next lecture is contained with the elongation and termination process..
hope you enjoyed.!