Many types of proteins can be isolated only in quantities that are too small for
ID: 708981 • Letter: M
Question
Many types of proteins can be isolated only in quantities that are too small for the direct
determination of a primary amino acid sequence. Recent advances in gene cloning and amplification
allow for relatively easy analysis of the gene coding for a particular protein. Why
would an analysis of the gene provide information about the protein's primary sequences?
Suppose that two research groups, one in New York and the other in Los Angeles, are both
analyzing the same protein from the same type of human cell. Why would you not be surprised
if they publish exactly the same primary amino acid sequence for the protein?
Explanation / Answer
Since the development of methods of high-throughput production of gene and protein sequences, the rate of addition of new sequences to the databases increased exponentially. Such a collection of sequences does not, by itself, increase the scientist's understanding of the biology of organisms. However, comparing these new sequences to those with known functions is a key way of understanding the biology of an organism from which the new sequence comes. Thus, sequence analysis can be used to assign function to genes and proteins by the study of the similarities between the compared sequences. Nowadays, there are many tools and techniques that provide the sequence comparisons (sequence alignment) and analyze the alignment product to understand its biology.
SAME SEQUENCE ANSWER-
DNA codes for RNA which codes for tRNA anticodons that are attached to the amino acid which will make up the polypeptide chain and ultimately the protein.
Basically, DNA is the blueprint that will ultimately decide which proteins will be made. Proteins are made up of sequences of amino acids. If two organisms have similar amino acid sequences, that means that they must have similar DNA that told the cells to make those amino acid sequences.