Textbook Chapter 5 Single Stranded RNA Bacteriophages Flashcards
when first discovered, single stranded RNA bacteriophages represented an ideal source of a purified messenger RNA for who?
molecular biology researchers
single stranded RNA bacteriophages have four genes on a what?
linear RNA of 3500-4200 nucleotides
RNA phages bind to F-pili and enter the cell how?
by release of RNA from the virion and probably by retraction of the F-pilus bound to viral RNA into the cell
Only the coat protein gene does what?
directly binds to ribosomes within the cell
alterations in secondary structures within phage RNA control what?
translation of the four phage genes
ribosomes translating the coat protein gene disrupt what?
secondary structure nearby the replicase gene start site, allowing ribosomes to bind to and translate the gene
ribosomes that terminate translation of the coat protein can do what?
scan forward or backward on viral RNA and initiate translation at the nearby lysis gene start site
translation of the maturation protein only occurs where?
on a newly synthesized viral RNAs during the short time when they have not yet folded into their stable secondary structure
Phage RNA polymerase contains what?
one viral protein subunit and three or four cellular protein subunits
Phage RNA polymerase binds where and what is the significance of this?
to start of the coat gene at the same site where ribosomes bind, significant because an RNA can either be replicated or translated but not both at the same time
