Silent but accused mutation
2007/02/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria
Scientists thought that mutation in a gene does not influence if it does not modify the basic protein sequence. However, as they have often seen the idea was corrupt.
In a paper published in the journal Science, researchers have shown that silent mutations, that is, those that do not alter the sequence of amino acids, sometimes influence and not in any way.
When a single nucleotide of DNA is modified and has no effect on the amino acid encoding that change, the mutation is said to be silent. The encoding of amino acids requires three nucleotides, whose combination determines which amino acids. There are several combinations per amino acid, so it is possible that a nucleotide changes, but that it generates the same amino acid. Consequently, there are also no changes in protein, since the amino acid chain has not changed. That in theory.
But actually something changes. To demonstrate this, researchers have studied the variants of the MDR-1 gene and have shown that its effect is different even having the same amino acid chain. Apparently, the mutant presents a somewhat different three-dimensional structure, taking into account the importance of the structure in the function, which explains the difference between the effects of one and the other.
