How do you identify amino acids from a protein structure?

Answer 1

The sequence of amino acids is determined by the mRNA transcript. By knowing what codon codes for each amino acid the RNA sequence can then be determined. From that the DNA sequence can be derived.

Answer 2

One method to determine a proteins amino acid sequence (primary structure) is the Edman degradation process. This method involves 3 steps:

1. Labeling of the proteins N-terminal amino acid residue in the protein using phenyl isothiocyanate (a strong electrophile that will react with the terminal amino group and attach an aromatic "tag").
2. Cleavage of the labelled N-terminal amino acid from the peptide chain using heat and acid. Under the conditions of this cleavage process the labelled amino acid will be converted to a very stable molecule called a phenyl thiohydantoin amino acid derivative.
3. Identification of the cut and labelled amino acid (phenyl thiohydantoin amino acid derivative) using chromatography.

When this process was first invented it was done step by step manually by a scientist. Now there is advanced technology that allows all of these processes to be done automatically in a protein sequencer. An ultra pure preparation of a specific protein is put into a piece of equipment that has been loaded with the correct chemicals and the start button is pushed. Of course this equipment is not cheap and often scientists will send their protein to labs that specialize in this technique, have the equipment and charge a reasonable rate to determine a sequence.


A second, more recently developed method of determining protein sequence (primary structure) is mass spectrometry. This method can also be simplified into three basic steps (VERY simplified here):

1. Bombardment of a batch of purified protein with a beam of electrons breaks the proteins into many smaller pieces, each of different size. These pieces all become ionized by this process, giving them each a charge.
2. The charged pieces are put through a detector/mass analyzer, which will determine the mass/charge ratio of each piece of the protein.
3. A computer will identify each protein piece by its mass/charge ratio and then use a complex computation to determine how all those pieces are arranged in the original protein. This is possible because each piece is a different size and there is overlap between all of the pieces. The pieces are lined up and arranged according to their areas of overlap to determine how the pieces were originally ordered.
   

Answer 3

Look up "The dictionary of the genetic code"

Answer 4

Sequencing the gene is an easy way to go now days. The triplet code is read for the amino acids and promoters to terminators of genes are easily identified these days.

Answer 5

chemical structure/particular code-like AUG--

Answer 6

Base sequence in DNA.