Last Wednesday an image of strange base pair was published on Discovering Biology in a Digital World [Puzzle]. We were asked to figure out what was so strange about his base pair (see below). I got part of the answer but not the complete answer.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEig2xETEE3-lV4R9tFjtZ0sEwZLoNB4Yd0kyF0bIgyxKiWMzqXpkrVeHJngxWxe7zrvmF6mRBdT479aGh3nyLTF3CdEJMBDm0MFmipaqaVLbzzE69qUjXHqsPlepOfXntlssDj7/s400/nucleic_acid_2.bmp)
The answer has already been posted but I won't link to it just yet in order to give you a chance to figure it out. Please don't comment if you've already seen the answer.
Here's another view that promises to be a lot more helpful.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgulR20LN2Rf0XKj7oy5JFu0z7z_6_jimfZ1xvmHS3Ki9URw93nvKdOeHNxZsV23L9Ut2vKzOkLbHUoJGG7jItm_wq3UEmHrOvP9Cgn0G7r73KpRRblZCnaCjR0ivU-0LPQUe_j/s400/nucleic_acid_1.bmp)
4 comments :
Whoa, that bottom one does give it away- wouldn't the strands containing that base pair have to be oriented parallel rather than antiparallel? That's bizarre. Is there actually a known duplex structure in which that's true? (I think there are RNA parallel triplex structures known, but I'm not aware of any kind of parallel duplex let alone a DNA one.)
Cool, eh? Yes, it's double-stranded DNA with parallel strands [It's Still a DNA Puzzle, but this is the Answer]. You can see for yourself by fetching 1r2l from the PDB or Nucleic Acid databases.
That is genuinely strange- thanks for the neat post.
Don't thank me. Thank Sandra Porter at Discovering Biology in a Digital World.
Post a Comment