Bacterial translational regulation (Moll)

What is 3rd base degeneracy?

The lesser effect of codon meaning of the nucleotide, present in the 3rd codon position, compared to the 1st and 2nd codon positions

Which codon(s) code for Tryptophane?

UGG

How is Tryptophane abbreviated?

Trp

What happens, when a base gets mismatched during Trp-synthesis?

It will most likely get converted into the Stop-codon

How many tRNA genes are there in the E. coli genome?

86

Unique feature of procaryotic tRNA

The 3’ CCA-end is encoded within the genome

How many isoacceptor families of tRNA are there in E. coli?

40

What is an isoacceptor family?

A group of tRNA molecules that can accept the same amino acid but have different anticodons

What is codon usage?

It describes, how often a codon occurs within the Open Reading Frame (ORF)

How is the secondary structure of tRNA called?

The cloverleaf structure

How is tertiary structure of the tRNA called?

L-form

What is Aminoacyl-tRNA-Synthetase?

An enzyme that attached the appropriate amino acid to its corresponding tRNA under the usage of ATP

What is kinetic proofreading?

tRNA/amino acid coupling control mechanism that depends on the fact that incorrect paiting events proceed slower than correct ones. The incorrect event is then reversed before the wrong amino acid is added to the polypeptide chain

What is chemical proofreading?

tRNA/amino acid coupling control mechanism that involves the hydrolysis of incorrectly formed aminoacyl-tRNA bonds. This happens after the incorrect amino acid is incorporated into the polypeptide chain

What is EFTu?

Elongation factor Tu that brings the charged tRNA to the ribosome

What is A-site?

Aminoacyl site on the ribosome that receives incoming tRNA molecules

What is P-site?

Peptidyl site on the ribosome where the tRNA holding the growing polypeptide chain is located

What is E-site?

Exit site on a ribosome that allows the uncharged tRNA to exit the ribosome

What is wobbling?

Variation from standard complementary base pairing rules between the 1st anticodon on tRNA and the 3rd codon on mRNA

What is suppressor tRNA?

tRNA that has a mutation in the anticodon that changes the codon it recognizes

What is the size of the procaryotic ribosome?

70S

What is the size of the small subunit of a procaryotic ribosome?

30S

What is the size of the small subunit of a procaryotic ribosome?

50S

What does small ribosome subunit in procaryotes consist of?

16S rRNA and 21 proteins

What does big ribosome subunit in procaryotes consist of?

5S and 23S rRNA and 31 proteins