Chapter Twelve Protein Synthesis: Translation of the Genetic Message

Aminoacyl tRNAs

________ are tested for their ability to bind in the presence of a given trinucleotide.

peptide bond

The ________ is formed, the P site is uncharged.

synthesis of polypeptide

In all organisms, ________ chain starts at the N- terminal end, and grows from N- terminus to C- terminus.

Start signal

________ is preceded by a Shine- Dalgarno purine- rich leader segment, 5- GGAGGU- 3, which usually lies about 10 nucleotides upstream of the AUG ________ and acts as a ribosomal binding site.

assay

Binding ________: aminoacyl- tRNAs bind to ribosomes in the presence of trinucleotides.

Amino acid activation

________ and formation of the aminoacyl- tRNA take place in two separate steps.

amino acid

First ________ is always methionine in growing polypeptide sequence.

Protein biosynthesis

________ is a complex process requiring ribosomes, mRNA, tRNA, and protein factors.

peptidyl tRNA

The ________ is translocated to the P site.

EF Tu

________ is released in a reaction requiring EF- Ts.

3 UAC

________- 5 triplet on tRNAfmet recognizes the AUG triplet (the start signal) when it occurs at the beginning of the mRNA sequence that directs polypeptide synthesis.

RF

________- 1 (Release factor- 1) which binds to UAA and UAG or ________- 2 (Release factor- 2) which binds to UAA and UGA.

________: if mRNA is polyU, polyPhe is formed; if mRNA is poly- ACACACACACACACACACACA-, poly (Thr- His) is formed.

Synthetic mRNA

A(n) ________ is bound to the A site.

aminoacyl tRNA

________- 3 which does not bind to any termination codon, but facilitates the binding of RF- 1 and ________- 2.

RF

aminoacyl-tRNAs bind to ribosomes in the presence of trinucleotides

binding assay

P (peptidyl) site, A (aminoacyl) site, E (exit) site

Uses three binding sites for tRNA present on the 50S subunit of the 70S ribosome