Nothing even little is useless... even in DNA

This is my first english-type post, so I hope you enjoy.

Figure 1.click on the image to get the abstract
It was so far accepted that dna-interacting proteins have to recognize some motifs within the DNA sequences that enable this interaction to be specific. It's been known that a DNA molecule is compose of two antiparallel strands that takes a defined tridimensional conformation and possesses two grooves within the molecule called the major groove and the minor groove. A particular sequence of nucleotide letters presents a unique array of hydrogen-bond donors and acceptors in the major groove, providing a clear mechanism for reading that sequence.


Recently, in a paper published in Nature the authors propose that not only the major groove but also the minor groove is responsible for dna-protein interaction due to the defined structure in the minor groove. Lets explain this in the next paragraph.

The width in the minor groove can vary depending on which nucleotides are present in segment of DNA. When the minor groove is narrow, the electric-field lines due to the negatively charged phosphates are focused into the groove, leading to a enhanced electrostatic potential within it (figure 2), allowing for residues like arginine present in the protein to interact with the minor groove. The authors also found that there are motifs of DNA sequences that results in a narrow minor groove, specially the so-called A-tracks (short runs of Adenine nucleotides) which have been implicated in DNA structure and nucleosome recognition.

Figure 2.The minor groove is directly involved in dna recognition.

In the paper cited above, it was used a equation to resolve the electrostatic potential of the minor groove and the difficulty of using this equation is that it requires high-resolution three-dimensional structures of proteins-DNA complexes.

After all, I encourage you to read the paper since it looks quite interesting, because, as many of the recent-published papers within the last months, this one shows us again that there are many stuff hidden in the DNA, waiting to be discovered.

Espero le entiendan, de cualquier forma les dejé los links para el paper y el comentario sobre éste (Figura 1).

Saludillos!!