quick virus question

[mayerrr]

I'm getting tripped up on a simple concept; there are DNA and RNA containing virus. DNA containing enter their DNA into the host (not nucleus), and in the cytoplasm, using the virus' own enzymes, replicates. But i'm also reading later that bacteriophages, which are DNA containing viruses, insert their DNA, and in the lytic cycle it says that they use the cells own machinery to replicate. Does this mean it uses the cells ribosomes and nucleotides and stuff in the cytoplasm, but the virus still has to bring its own RNA polymerase (since this is restricted to the host nucleus)?

 

Thanks

[Asta]

I'm getting tripped up on a simple concept; there are DNA and RNA containing virus. DNA containing enter their DNA into the host (not nucleus), and in the cytoplasm, using the virus' own enzymes, replicates. But i'm also reading later that bacteriophages, which are DNA containing viruses, insert their DNA, and in the lytic cycle it says that they use the cells own machinery to replicate. Does this mean it uses the cells ribosomes and nucleotides and stuff in the cytoplasm, but the virus still has to bring its own RNA polymerase (since this is restricted to the host nucleus)?

 

Thanks

 

If you are talking about bacteriophages in particular, there is no nucleus. Just keep in mind that viruses have either RNA or DNA, they don't have both. I don't know if that helps you at all.

[thehumanmacbook]

I'm getting tripped up on a simple concept; there are DNA and RNA containing virus. DNA containing enter their DNA into the host (not nucleus), and in the cytoplasm, using the virus' own enzymes, replicates. But i'm also reading later that bacteriophages, which are DNA containing viruses, insert their DNA, and in the lytic cycle it says that they use the cells own machinery to replicate. Does this mean it uses the cells ribosomes and nucleotides and stuff in the cytoplasm, but the virus still has to bring its own RNA polymerase (since this is restricted to the host nucleus)?

 

Thanks

 

I've answered this question regarding the different types of viruses before to user kkentm, so I think if you look it up it's probably somewhere - but I'll try my best here.

 

If you're discussing bacteria - they don't have a nucleus (prokaryote). Hence the RNA polymerase should be floating around somewhere in the cytoplasm, and the DNA virus is free to use it to replicate. This is grossly oversimplified, but it should be good enough for the MCAT.

[mayerrr]

wow, i'm an idiot

[pacemaker]

So, if there is a virus with RNA that infects a eukaryotic cell (one that has a nucleus), then the virus has to bring in its own RNA polymerase since the virus genome gets injected into the cytoplasm of the host and can't really enter the host nucleus where the host RNA polymerase is likely to be located. Right?

[thehumanmacbook]

So, if there is a virus with RNA that infects a eukaryotic cell (one that has a nucleus), then the virus has to bring in its own RNA polymerase since the virus genome gets injected into the cytoplasm of the host and can't really enter the host nucleus where the host RNA polymerase is likely to be located. Right?

 

Yes. What you're talking about is called a "negative strand" type virus that brings in its own polymerase in addition to coding for it in its viral mRNA. One example is rabies. However, this is just one strategy - not all viruses that infect eukaryotic cells need to use this format to replicate.