Non-standard decoding and ribosomal gymnastics Flashcards Preview

BS2091 Biochemistry I: from genes to proteins > Non-standard decoding and ribosomal gymnastics > Flashcards

Flashcards in Non-standard decoding and ribosomal gymnastics Deck (16):
1

Give an example of a plant RNA virus

Tobacco mosaic virus (TMV)

2

What does TMV require?

An RNA-dependent RNA polymerase ('replicase')

3

Is TMV a positive or negative strand virus?

(+) strand virus, i.e. RNA acts as mRNA

4

What does the TMV encode?

A coat plus replicase etc.

5

What is the size of the TMV replicase protein?

126 KDa

6

The TMV replicase gene undergoes..

Programmed stop codon readthrough

7

The leaky UAG at the end of the replicase 'gene' product =

183 KDa = essential protein

8

What does a 'slippery sequence' do?

Causes ribosomes to slip backwards minus 1 frameshift

9

What efficiency does a -1 frameshift have?

50% efficiency

10

Are retroviruses RNA or DNA viruses?

RNA viruses

11

Is RNA translated by retroviruses?

No

12

Viral ssRNA is converted to what in retroviruses?

dsDNA

13

What enzyme do retroviruses need to convert ssRNA to DNA-RNA to dsDNA?

Reverse transcriptase (RT)

14

The dsDNA product produced by the reverse transcriptase of a retrovirus is integrated into..

The genome and expressed normally via transcription and translation

15

What are Gag and Pol products?

Polyproteins

16

What is the ribosome's PB?

PB = 'personal best' as in athletic performance