Monday, June 18, 2007

Monday's Molecule #31

Today's molecule is complicated but it makes a lot of sense if you know your basic biochemistry. We don't need a long complicated name this time. It's sufficient to simply describe what you're looking at and why it's significant. You have to identify the key residue to get credit for the answer.

As usual, there's a connection between Monday's molecule and this Wednesday's Nobel Laureate(s). This one is an obvious direct connection. Once you have identified the molecule you should be able to name the Nobel Laureate(s).

The reward (free lunch) goes to the person who correctly identifies the molecule and the reaction and the Nobel Laureate(s). Previous free lunch winners are ineligible for one month from the time they first collected the prize. There are no ineligible candidates for this Wednesday's reward since recent winners (including last week's winner, "Kyo") have declined the prize on the grounds that they live in another country and can't make it for lunch on Thursday (a feeble excuse, in my opinion, haven't you heard of airplanes?).

Comments will be blocked for 24 hours. Comments are now open.

UPDATE: The molecule is the lariat structure of the RNA splicing intermediate. The key residue is the adenylate residue that's joined through its 2′ hydroxyl group to the 5′ end of the intron [see RNA Splicing: Introns and Exons]. The Nobel Laureates are Rich Roberts and Phil Sharp. (See the comments for an interesting anecdote concerning the discovery of this molecule.)


  1. Well, there's RNA and protein, so a riboprotein? The reaction would be some sort of catalysis, because the Nobel Laureates are Cech and Altman, who are credited with discovering the catalytic properties of RNA. Both of them studied splicing.

    Crossed fingers!

  2. An RNA Lariat, it looks more like. The reaction would be splicing. Cech and Altman.

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  4. This is an RNA lariat which is formed from the splicing of introns from pre-mRNA. The Nobel for this discovery went to Rich Roberts and Phil Sharp in 1993. The structure was discovered simultaneously in two labs: Sharp at MIT and Michael Green (then at Harvard). First author on Green's paper was Barbara A. Ruskin--my 4th year lab partner in our advanced biochemistry lab course at Berkeley. Tony Percival-Smith and I were visiting Michael Ellison in Cambridge, MA in January of 1984 and dropped by to visit Barb in her lab. She showed us the autorad of a sequencing gel where she had used Reverse transcriptase to sequence the gel-purified "mysterious" RNA splicing intermediate. When it was published there was a crayon drawing (of the type favoured by Hal Weintraub) on the cover of the journal Cell.

    The Nobel Prize awarded to Tom Cech and Sid Altman in 1989 was for the discovery of catalytic RNA (a previously unanticipated chemical activity for this moiety). I was a post-doc in Boulder, CO and the department had a huge party on a grassy lawn with free cake and champagne to celebrate Tom's award.

    As you are probably aware, Nobel prizes for science follow academic lineages. My post-doctoral mentor, Bill Wood, of bacteriophage T4 fame, trained with Paul Berg (Nobel Prize, 1980), and Werner Arber (Nobel Prize, 1978), which statistically greatly enhances Bill's chances of winning. Whether this carries through to the next generation (i.e., me) remains to be seen.

  5. Marc Perry, the famous textbook author, wins a free lunch. Come to my office tomorrow at noon.

    Neither my graduate supervisor (Bruce Alberts) nor my post-doctoral supervisor (Alfred Tissières) won Nobel Prizes. That means I don't have a chance.

    Incidentally, Bill Wood may be famous for lots of things but the best by far is that he once made a record with an unknown singer named Joan Baez.