Today, we're going to look for rainbows in double-stranded DNA and see what they can tell us about DNA structure.
First, we're going to get a structure for a double-stranded molecule of DNA and open it in Cn3D.
If you want to do this at home and you haven't already downloaded a copy of Cn3D, you may want to read these instructions and get a copy. These directions ... Read more
Why do I love Cn3D? Let me count the ways.
What does Cn3D do? (Hint: say "Cn3D" out loud).
Seriously, Cn3D is a program that draws lovely pictures of molecular structures by using experimental data from techniques like X-ray crystallography and nuclear magnetic resonance spectroscopy. Surprisingly (to some), and in contrast to many bioinformatics programs, Cn3D is really easy and fun to use.
Have you ever used programs like MS Office? Using Cn3D is at least 10 times easier.
An added benefit is that you don't have to try and find old copies ... Read more
How can you win a nerd contest if you don't dress the part?
Last year, I started a shop at CafePress to help distribute lab materials and fund my adventures in science education. Part of the fun has been making molecular merchandise to help show everyone that molecular models are beautiful, in their own special way, and help people engage in random acts of science education.
Here are some of my suggestions for molecular wearables that can help you ... Read more
Did HIV become resistant to Atazanavir because of a genetic change?
Was that genetic change inherited?
Did HIV evolve?
Can we explain why genetic changes at specific sites might help HIV escape the effects of the drug?
Let's find out.
All of the sequences in the image below (except for the first) come from HIV strains that were isolated from patients who took Atazanavir and no other protease inhibitors. All of the strains of HIV from patients were resistant to the drug.
If an amino acid is different from other strains, the color at that position is changed. ... Read more
When can a really bad virus be used to do something good?
When we can use it to learn.
The human immunodeficiency virus, cause of AIDS, scourge of countries, and recent focus of ScienceBlogs; like humans, evolves. As one ... Read more
One of the commenters on a previous post, pointed out that proteases have pretty diverse structures, even though they also share a common function.
What else could I do? I had to take a look. I found structures for chymotrypsin (from a cow) and subtilisin (from a soil bacteria, Bacillus lentus) and used Cn3D to see how they compare (below the fold).
Both enzymes are proteases - that is they cut the peptide bonds in proteins that hold amino acids together. Many of you use ... Read more
It seems kind of funny to be thinking of anti-freeze at the moment, with heat waves blanketing the U.S., but all this hot weather makes me miss winter. And so I decided it was time to re-post this from the original DigitalBio.
Winter is coming soon, my bike ride to work was pretty chilly, and it seems like a good time to be thinking about antifreeze. Antifreeze proteins, that is. Antifreeze proteins help keep pudgy yellow meal worms from turning into frozen wormsicles and artic flounder from becoming frozen flat fish.
Although, I certainly didn't believe it. Truly in nature, it can be described as nonpareil.
With all the years that I've heard (or taught) that all DNA is antiparallel, it was hard to believe my own eyes when I saw this structure.
Yet here is, on the screen, parallel DNA.
The image that I posted a couple of days ago came from this same structure. In that image ... Read more