Fusion in Frame: What Does it Mean?

[mountain]

fusion in frame...?

hi guys!

i am new in this field, so i hope that "mature" people can show me the way. thanks in advance!

with fusion in frame does it mean that the nucleotide sequences of both DNA fragments i fuse with each other have to act as independent triplet unit? in this way we can maintain the polypeptide of both DNA fragments? in other words that their nucleotides don't come together to make the triplet codons from the start to the end no matter if the fusion is a C, N or randomly (please see example 1, below).

for instance if the nucleotides of DNA fragment 1 is k's and it is a plasmid and nucleotides of DNA fragment 2 is x's. i insert 2 into 1. should i before the fusion have to make sure that the DNA fragments i fuse have enough nucleotides each to make their own triplets codon?:

example 1: randomly fusion where i insert DNA fragment 2 in the middle of the plasmid:
...kkk kkk kkk xxx xxx xxx xxx kkk kkk kkk...
here we get inframe from the start to the end. is this the ideal fusion? we can see here that the nucleotide sequences of both fragments DON'T COME TOGETHER TO MAKE THE TRIPLET CODONS. they act as independent units. the polypeptides of both fragments are maintained.


example2: in this case i have used a fragment which does not have enough nucleotides to make the triplet codons for its own. that is why it come with the nucleotides of the plasmid to make the triplet codons. AND THIS IS A FUSION WE SHOULD AVOID, RIGHT? because the polypeptides of fragment 2 is changed, so do the plasmid.
...kkk kkk kkk xxx xxx xxk kkk kkk...


i try to shorten this down, but afraid that none will understand my point, so please be patient and read


thanks alot!

 

[iansmith]

Example 1 is usually what you are aiming for fusion protein. In example 2, you would have a reading frame shift which you change the C-terminal of the protein and the mRNA might have a premature stop codon, have no stop codon or the stop codon will be further than the normal frame.

 

[ravenprp]

Fusion in frame refers to the joining of two or more DNA fragments in a way that maintains the reading frame of each fragment. This means that the nucleotide sequences of the fused fragments should be able to act as independent units, without overlapping or interrupting the triplet codons that code for amino acids. In other words, the nucleotides of each fragment should not come together to make new triplet codons, but rather maintain their original codons and preserve the polypeptide sequences of each fragment.

In your example, randomly fusing the two fragments in the middle of a plasmid would result in an ideal fusion because the nucleotide sequences of both fragments are able to act as independent units and maintain their polypeptide sequences. However, if the fragments do not have enough nucleotides to make their own triplet codons, they may use the nucleotides of the plasmid, resulting in a fusion that should be avoided because it changes the polypeptide sequences of the fragments and the plasmid.

It is important to ensure that the fragments being fused have enough nucleotides to maintain their own triplet codons and preserve their original polypeptide sequences. This will result in a successful fusion and avoid any unwanted changes to the polypeptide sequences. I hope this helps clarify the concept of fusion in frame. Good luck with your studies!