Concepts about the Vector - (Apr/13/2008 )

I have pcDNA 3.1 vector can some one guide me the function of its different components
pCMV is promotor, does it is constitutive promotor, its strong ok but why it is so famous else.
BGH pV????
Why there is need of three different origin of replication SV40, f1 and pUC ori already there.
whats is BGH pA (for poly A tail), but if cDNA has its own poly A tail then it will work or not.

I shall be very thankful to you for your kind reply.

though i dont know the function of each component, i still can add my opinion. rest will be added by other members. SV40 ori is not a bacterial ori. as far as i know, its for the episomal replication in eukaryotic cells. as for the presence of f1 and PUC at the same time, i dont have much concept. CMV promoter is a constitutive one and is famous because it has been shown to express variety of different genes in variety of different of animals and tissues. its is actually famous for its multiplicity and strength of expression it provides. to put it in a nutshell, it is famous because it is WORKING very well.
now coming to the BGH PA. I think if you have a PA tail in ur cDNA, BGH PA will not do any harm. it is just a PA signal and ur cDNA PA tail will be read as part of ORF by the enzyme and the BGH PA will cause addition of some more adanines at the 3' end and a more stable RNA.
i hope it will help u. me too wud be looking for some more learned views on the subject

Thanks for the answer. Its really very nice to learn all aboout it form you and others as well.