Playing with the components of the structure of life

2001/04/04 Roa Zubia, Guillermo - Elhuyar Zientzia

• Genetika
• Kimika

A group of American scientists from Buffalo have developed a method to introduce new laboratory amino acids into proteins. These amino acids are new because they are not natural. Invented amino acids can act as protein markers. In addition, artificial proteins may be made to perform functions that do not play in nature. It can be an opportunity for biochemical engineering.

The problem is that natural proteins are encoded in genes. Artificial proteins should also have their own genetic code in order to synthesize bodies as natural. Organizing it is not an easy task.

In the natural system the information is stored in the DNA molecule (genome). The information is copied and taken to the ribosomes, where proteins are produced. Amino acids are taken one by one and, interconnected with the previous one, the protein chain is formed in the right order. This work is performed by RNA molecules. Therefore, the challenge of scientists was to seek a method of natural association between artificial amino acids and RNA.

There are several types of RNA. One of them, the transfer RNA, takes the appropriate amino acid and transports it to the ribosomes. In them it is associated with the protein chain. Scientists at the University of Buffalo have discovered that unnatural amino acids can follow the same process through another fragment of harness.

This work has been an important consequence, since in this case, at least, the information contained in the DNA is not necessary. This conclusion corresponds to an idea that is lately in scientific debates. What was the first molecule of life?

At the biochemical level, life requires a molecule capable of copying itself. The information is provided by the DNA molecule, but it needs proteins to be copied. Proteins can work but have no information to do so. DNA needs proteins and proteins need DNA. It is the same dilemma as chicken and egg.

But this dilemma has been answered. The RNA molecule is not a simple copy of DNA. It also has the ability to perform jobs (what chemicals call catalytic capacity). Therefore, the origin of life at the molecular level could be in RNA. This theory is gaining more and more strength in the scientific community, although some geneticists still do not want to leave the world of DNA.