HIV-1 genome revealed

Researchers have long probed the structure of viruses like HIV piece by piece, separating them out to examine their function.

Now, for the first time, a team of researchers led by Kevin Weeks of the University of North Carolina have zoomed out to give a holistic view of the entire genome for HIV-1.

This 'aerial' view will enable scientists to look at how the higher-order 'secondary' structures also affect the function of the virus.

Traditional techniques for probing the structure of biomolecules, such as nuclear magnetic resonance and x-ray crystallography have limitations when it comes to examining large structures, so the team used a technique called SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension) to decode the genome structure at the single nucleotide level.

SHAPE produces lower resolution images than yielded by other techniques, but it is uniquely able to capture the entire genome structure with sufficient resolution to show previously unrecognised structured motifs, such as stems and loops, in regulatory and protein coding regions of the virus.

The composition of nucleotides influences protein production, but the team also show that protein translation and folding are influenced by these structural elements within the RNA. This suggests that RNA structure may have a previously unappreciated role in the expression of the genetic code.

The article was published today in the journal, Nature.