More Recent Comments

Monday, April 02, 2012

Monday's Molecule #164

What is this structure and what is its significance? You don't need to come up with a chemical name but you do need to be as specific as possible.

Don't forget to tell us why this structure exists.

Post your answer in the comments. I'll hold off releasing any comments for 24 hours. The first one with the correct answers wins. I will only post correct answers to avoid embarrassment. The winner will be treated to a free lunch.

There could be two winners. If the first correct answer isn't from an undergraduate student then I'll select a second winner from those undergraduates who post the correct answer. You will need to identify yourself as an undergraduate in order to win. (Put "undergraduate" at the bottom of your comment.)

Some past winners are from distant lands so their chances of taking up my offer of a free lunch are slim. (That's why I can afford to do this!)

In order to win you must post your correct name. Anonymous and pseudoanonymous commenters can't win the free lunch.

Winners will have to contact me by email to arrange a lunch date.

Comments are invisible for 24 hours. Comments are now open.

UPDATE: The molecule is the cap structure on the 5′ end of eukaryotic mRNAs. It's actually a CAP 2 structure with methyl groups at the 2′ positions of the last two nucleotides but that terminology seems to be outdated so I won't insist that you specify. (Thanks to Bill Chaney for getting it right.) The winner is Sean Ridout. (Please contact me by email.)

Nov. 2009: Jason Oakley, Alex Ling
Oct. 17: Bill Chaney, Roger Fan
Oct. 24: DK
Oct. 31: Joseph C. Somody
Nov. 7: Jason Oakley
Nov. 15: Thomas Ferraro, Vipulan Vigneswaran
Nov. 21: Vipulan Vigneswaran (honorary mention to Raul A. Félix de Sousa)
Nov. 28: Philip Rodger
Dec. 5: 凌嘉誠 (Alex Ling)
Dec. 12: Bill Chaney
Dec. 19: Joseph C. Somody
Jan. 9: Dima Klenchin
Jan. 23: David Schuller
Jan. 30: Peter Monaghan
Feb. 7: Thomas Ferraro, Charles Motraghi
Feb. 13: Joseph C. Somody
March 5: Albi Celaj
March 12: Bill Chaney, Raul A. Félix de Sousa
March 19: no winner
March 26: John Runnels, Raul A. Félix de Sousa
April 2: Sean Ridout


  1. This is a 5' 7-methylguanylate cap found in eukaryotic mRNA. It plays roles in the regulation of eukaryotic mRNA export, in protecting the mRNA from 5'-3' exonucleases, and in promoting translation (eIF-4E binds to the cap to facilitate initiation of translation).

  2. This comment has been removed by the author.

  3. It appears to be the 5' RNA cap. It is involved in nuclear export of the RNA, and in initiation of translation. It also protects the RNA against exonoclease digestion and promotes intron excision in the 5' proximal region.


  4. The structure is the 5' cap (7' methyl guanosine triphosphate) and its significance is for being an specially altered nucleotide on the 5' end of precursor messenger RNA and some other primary RNA transcripts as found in eukaryotes. The process of 5' capping is vital to creating mature messenger RNA, which is then able to undergo translation. Capping ensures the messenger RNA's stability while it undergoes translation in the process of protein synthesis, and is a highly regulated process.

  5. It is the 7-Methyl-G cap of many eukaryotic messenger RNA molecules. With two ribose residues O-methylated, this is a cap-2 structure.

    When the cap-binding protein binds to it, it signals that this is a mRNA and that translation will start near that end.

  6. A 7-methyl guanosine joined in a 5' to 5' orientation to the 5' end of a eukaryotic mRNA. The cap is needed for export of the mRNA to the cytoplasm (?) and is used by the small ribosomal subunit to recognize and bind to the mRNA during translational initiation (?).