Wednesday, February 25, 2009

Monday's Molecule #109: Winners!

UPDATE: The molecule is the Klenow fragment of E. coli DNA polymerase I. It's the part of the enzyme that's missing the 5′→3′ exonulcease activity. The Nobel Laureate is Kary Mullis, one of the most eccentric scientists ever to win a Nobel Prize—and that's saying a lot because Nobel Laureates are a very unusual group.

The winner is Guy Plunket III from the University of Wisconsin. There was no undergraduate winner this week so I awarded the second prize to Deb McKay, who is currently teaching in a Toronto high school. Her answer wasn't perfect but she offered me a bribe I couldn't refuse.1

Today's molecule is actually two molecules but we only care about the protein. You need to identify this protein, being as specific as possible. A general description of the type of protein won't do because the image clearly show a particular version.

There's are several possible Noble Laureates associated with this molecule. One of them was Michael Smith—last week's Nobel Laureate. The person I'm looking for was never a Professor. That's not necessarily a bad thing, it just helps you narrow down the field of possible prize winners.

The first person to identify the molecule and the Nobel Laureate wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first won the prize.

There are seven ineligible candidates for this week's reward: John Bothwell from the Marine Biological Association of the UK, in Plymouth (UK), Wesley Butt of the University of Toronto, David Schuller of Cornell University, Nova Syed of the University of Toronto, Dima Klenchin of the University of Wisconsin and undergraduate Alex Ling of the University of Toronto, and James Fraser of the University of California, Berkeley.

John, David, and Dima have offered to donate their free lunch to a deserving undergraduate so I'm going to continue to award an additional free lunch to the first undergraduate student who can accept a free lunch. Please indicate in your email message whether you are an undergraduate and whether you came make it for your free lunch (with a friend).


Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureate(s) so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow. I reserve the right to select multiple winners if several people get it right.

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

1. A sneak peek at the new science curriculum for Ontario schools. Were you thinking of something else, perhaps?


  1. Damn it...I got the laureate right but not the molecule

  2. The molecule is pretty easy, actually. It's clearly a polymerase of some sort, and since the Laureate is obviously Mullis, then it must be DNA polymerase. An even bigger clue is the fact that it has exonuclease activity. In fact, the picture even tells you what exonuclease activity is has, and it is clearly missing the 5'->3' exonuclease activity. And if you've ever taken molecular biology, that's obviously the Klenow fragment.

    If I were a structural nerd, it might even be more obvious. But the above logic process was how I did it.

  3. Well, I did say Taq polymerase but did not discern the Klenow fragment. I guess the missed the 5'-3' part.

  4. It's not Taq polymerase. That enzyme wasn't used until a few years after PCR was first developed.

  5. TAQ doesn't have 3'-5' exonuclease activity either.