Chapter 5 Flashcards
ss-RNA Bacteriophage
leviviridae infects
gram (-) bacteria
leviviridae has two groups:
levivirus (MS2) and allolevivirus (QB)
viral proteins of leviviridae:
1) coat protein with T=3; 2) maturation protein of 1 copy; 3) lysis protein; 4) replicase (RdRp)
host attachment with F-pili
cleaves Maturation protein into 2,then RNA released from virion to get inside of the cell.
the maturation protein is located on
the five-fold axis with 1/12 possibility.
CP readthrough (A1) for QB occurs at:
1742, with UGA -> Trp (UGG) by 6%
ribosome binding sites:
AUG start codons with fMet-tRNA anticodon in ribosome, Shine-Dalgarno sequences with 3’-end of 16S rRNA, and Upstream Pyrimidine-rich sequences -> S1 r-protein
consensus of SD is
AGGAGG
Order in Translation of MS2:
coat protein -> Replicase -> Lysis protein -> Maturation protein upon replication
Regulation involving alternative RNA structure
replicase and maturation proteins translation
Regulation involving protein-RNA interaction
[CP] increasing consquently repress replication translation by binding to its Oh
Regulation involving ribosome reinitation
lysis protein translation
Replication of QB genome follows:
(+) to (-) to (+) progeny
QB genome replication polymerase complexes are
Replicase, EF-Tu, EF-Ts, S1, Host factor
The first replication requires:
Replicase, EF-Tu, EF-Ts, S1, Host factor
