Exam 17: The Mechanism of Translation I: Initiation

Which of the following initiation factors prevents reassociation of the 70S ribosome by binding to the free 30S subunit?

The Shine-Dalgarno sequence can be found in

Regions within mRNA that can bind small molecules to change conformation and thereby change gene expression are called_____________.

In prokaryotes the first amino acid in all mature proteins is an N-formyl-methionine.

Very stable mRNA ______________ between the Cap and the initiation site can block ribosomal scanning.

tRNA charging is the addition of a(n)___________ to the 3'end of a tRNA molecule.

Prokaryotic mRNAs contain a short RNA sequence upstream from the initiation codon called the ______________ sequence,which is complementary to a sequence on 16S rRNA.

Translational control is more common in prokaryotes than eukaryotes because prokaryotic mRNAs have a longer lifetime than eukaryotic mRNAs.

_________________ studies have shown that eIF3 is a five-lobed protein that binds to eIF4G and to viral IRES.

Match the following eukaryotic translation initiation factors with their correct function. -This initiation factor is involved in binding tRNA to the ribosome.A

Put the following steps of prokaryotic translation initiation in the correct order.(1)Binding of IF1,IF2,and GTP to the 30S subunit.(2)Binding of IF3 to the 30S subunit.(3)Binding of the 50S subunit and loss of IF1 and IF3.(4)Dissociation of the 70S ribosome.(5)Formation of the 70S initiation complex by dissociation of IF2 and GTP hydrolysis.(6)Formation of the 30S initiation complex.

Phosphorylation of eukaryotic initiation factors can play both an inhibitory and stimulatory role in translational control of gene expression.

Translation takes place in the _________________ of prokaryotes and in the _____________ of eukaryotes.