Jump to content

  • Log in with Facebook Log in with Twitter Log in with Windows Live Log In with Google      Sign In   
  • Create Account

Submit your paper to J Biol Methods today!
Photo
- - - - -

Why are there two origin of replications in plasmids


  • Please log in to reply
3 replies to this topic

#1 pattycakes

pattycakes

    member

  • Members
  • Pip
  • 2 posts
0
Neutral

Posted 05 December 2014 - 06:05 PM

Hi,

I'm new here. And I keep looking around for a specific answer for why there two origin of replications in plasmids? 

 

Thank you!

P.S. I know this might be such a simple question to answer.



#2 phage434

phage434

    Veteran

  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 2,504 posts
252
Excellent

Posted 05 December 2014 - 07:19 PM

What plasmids are you thinking of? Some have multiple replication origins which are functional in one or another species (such as E. coli/yeast shuttle plasmids). Some, such as the rolling circle plasmids, have a positive origin, which copies the plasmid producing a long single stranded DNA strand, and a separate negative origin, which initiates to produce the complementary strand. You'll have to be more specific about the plasmid for this to have a solid answer.



#3 pattycakes

pattycakes

    member

  • Members
  • Pip
  • 2 posts
0
Neutral

Posted 05 December 2014 - 09:11 PM

Sorry. For example, pet28a has two origin of replication (f1, PBR3286)



#4 phage434

phage434

    Veteran

  • Global Moderators
  • PipPipPipPipPipPipPipPipPipPip
  • 2,504 posts
252
Excellent

Posted 06 December 2014 - 07:33 AM

The pBR322 origin is active in replicating the plasmid under normal circumstances. The F1 origin is only active if the cell is co-transformed with a phage, such as the helper phage M13K07. Then, the F1 origin initiates a single stranded copy of the plasmid, which can be packaged into M13 phage particles. This is pretty much unused today, but was very important in the early days of sequencing, when the sequencing protocols required single stranded DNA substrates.






Home - About - Terms of Service - Privacy - Contact Us

©1999-2013 Protocol Online, All rights reserved.