what information about the primary structure of protein is not available from the DNA sequence?

Question

what information about the primary structure of protein is not available from the DNA sequence?

Answer 1

So, from the DNA sequence of a gene one can figure out the exons and introns. Combine the exons to get the open reading frame of the encoding RNA. The ORF contains an ATG followed by a bunch of codons encoding for amino acids, followed by a stop codon, and usually a poly adenylation sequence. Less conserved is the ribosomal binding site at the 5' of the RNA. From such data you can gleen out secondary and tertiary structural information. Secondary structure mostly maps well with computer modelling, and lately some tertiary structure (the 3d structure of the protein) has been mapped for small proteins. Also you can make predictions about post-translational modifications such as phosphorylation, but I would say this information is not that reliable unless a sequence is really conserved. Predicting phosphorylation sites is very black-box voodoo; in the protein I studied we identified one site because it had a very well conserved consensus sequence around the phosphorylation site, although the sites we found in vivo did not show up using computer models. Anyway I would say that post-translational modifications are the answer to the question, but the question is pretty vague.

Answer 2

The amino acid and order are given by DNA. I worked with one professor who thought the way the protein wrapped, twisted, physically structure was also in the DNA somewhere. Maybe in the unknown part or a different decoding of DNA.

Answer 3

In your cells there is also RNA... while this is usually coded from the DNA, there are often strands that are seperate from this... such RNA is present in mitochondria and viruses.



Mitochondria is what gives your body most of its energy and the proteins in it are not coded from the cell's DNA but is rather coded by its own set of RNA. It is suspected that mitochondria are actually invading simple cells that coexist with us from billions of years ago... but no one knows.



Viruses are actually pieces of RNA and DNA that invades the call and then changes protein production to the extent that new proteins can be formed or normal proteins are not produced.



These are the only two ways i know of that proteins can be formed without first replicating the DNA with mRNA.

Answer 4

i disagree with the above answer, as one can determine the specific amino acids by looking at the base triplets of a DNA sequence, as every base triplet ie/ ATG or CTG, can be tracked to a specific amino acid.

Answer 5

there isn't information loss on the DNA sequence. Tth polymerase enzyme and primer help in that