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Cheatography

Translation: mRNA to Protein Cheat Sheet (DRAFT) by

Briefly described process of translation of mRNA into polypeptides

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Intodu­ction

The mRNA is read according to the genetic code, three bases at a time [codon] each of which refers to an amino acid
Occurs in the cytoplasm of the cell
Produces polype­ptide which undergo folding to become functional protein

Key Machin­eries

mRNA
Transc­ribed from DNA
Ribosome
Large & Small sub-units
 
*Large sub-unit A-[Aminoacyl]-site, P-[Peptidyl]-site, E-[Exit]-site
 
*Small sub-unit latches onto mRNA, forms the initiation complex
tRNA
Carrying Amino acid specified by anti-codon
GTP
supplies energy as hydrolyzes into GDP

The Process

Can be split into 3 steps as follows:
Initiation
Elongation
Termin­ation

Step 1: Initiation

The Sequence
Small sub-unit looks for initiator seq.
 
In Prokar­yotes, Shine-­Dal­garno seq.
In Eukary­otes, Kozak seq.
tRNA #1
Charged with an N-form­ylated Methionine
Called only by initiator AUG
 
Initiation Factors
IF-3
Prevents binding of large sub-unit thus allowing small sub-unit to bind with mRNA
 
IF-2
Forms a complex with f-MettRNA & GTP and binds with the small sub-unit
 
IF-1
Joins in after f-MettRNA arrives at iniati­ation codon AUG