RNA, 50 years in the making

2006 was (again) year of the RNA.

Two nobels. The RNA world expanded with the discovery of Piwi RNA. RNAi as a transmittable trait? (Lamarck is vindicated!) We also found out that much of the conserved parts of our genome do not encode protein. Now how many of these bits are regulatory elements and how many are non-coding RNAs is yet to be tabulated. However the most rapidly evolving gene between humans and chimps is one of these non-coding RNA. There are even hints that the lowly centrosome has it's own RNA (although flies apparently don't need centrosomes.) Also a nice theory was proposed that links the appearance of the eukaryotic nucleus as a method to separate mRNA synthesis and processing from mRNA translation. AND one of the coolest papers demonstrated that misfolding of a newly made translational product inside the ER activates transcript specific degradation across the ER membrane.

But this year also marks the 50th anniversary of the RNA double helix structure (you can read about it in this month's edition of The Scientist). You might think "no big whoop", but Alexander Rich and David Davies also performed the first hybridization experiment ever. From Alexander Rich's article:

While I was more focused on what we would see in the X-ray pattern, what happened in that tiny droplet was arguably more remarkable. Without any energetic input we had watched two negatively charged molecules spontaneously zip together. Though there wasn't even a name for it at the time, Davies and I had observed hybridization.

...

Some colleagues were shocked. I had stopped Herman Kalckar in the long corridor at NIH to tell him we had discovered that polyribo A and polyribo U combined spontaneously to make a double helix. The Danish biochemist had to hold on to his pipe as he responded, "You mean without an enzyme?" Corralling these long tangles into neatly ordered helices worked against entropy. And though it was completely reproducible, some scientists were still skeptical, but not all. After presenting the material at a meeting several months later, Julian Huxley, the English scientist and writer, came up and congratulated me for having discovered "molecular sex."

This idea was very important. As Rich states:

The simple hybridization reaction has made possible most of the molecular biological revolution.

Think PCR, sequencing, fluorescent in situ hybridization, southern blots ...

And the work on the RNA structure became important. After 17 years of improving the technique:

In 1973, synthetic nucleic acids were not available. However, my students and I found that we could crystallize helical fragments of RNA. We reported the crystal structures of GpC and ApU, both forming fragments of an RNA double helix and both solved at 0.8 Ãngstrom resolution.9,10 These structures showed unequivocally that Watson-Crick pairing was found when the molecules organized in an RNA double helix. The results elicited a call from Watson in which he told me that, upon reading preprints of our manuscripts, he'd had his first good night's sleep in twenty years.

Also check out this RNA Timeline.

AND ... if I missed any major RNA related news from this year, please ad it to the comment section.