It appears that there are three forms, A, B and Z. With B being normal, A appearing in dehydrated DNA or pairing of DNA and RNA, and Z appearing in methylated DNA which is identical to B but for the direction of the twist.
BTL or some else can likely give a better answer...
Posted by rivka (Member # 4859) on :
quote: A-DNA family - this is most common for double stranded RNA, RNA/DNA hybrids, as well as for certain DNA sequences, such as long stretches of purines.
B-DNA family - DNA exists in the "B-DNA form", most of the time inside the cells of living organisms. This is the classical "Watson-Crick" structure.
Z-DNA family - this is much more rare than the other two families, although certain sequences (such as runs of GC repeats (GCGCGC)) can form Z-DNA easily.
Posted by Shigosei (Member # 3831) on :
Well, that mostly confirms what I thought I knew, although supposedly A-DNA also occurs near sites of transcription. I'm off to give my presentation now...wish me luck!
Posted by rivka (Member # 4859) on :
How did it go?
Posted by Shigosei (Member # 3831) on :
Quite well, thanks! The professor I work for, the grad student who works most closely with me, and some of the other grad students in the lab showed up to watch me speak. The grad student even asked a question he darn well knew the answer to . But afterward, he told me I had given the best explanation of X-ray crystallography that he had ever seen from an undergrad/high school student (I started working in this lab as a junior in high school). The professor was also pleased with my presentation. If anyone wants to see the power point I used, I'll be happy to e-mail it to them.
Posted by rivka (Member # 4859) on :
Excellent! Posted by Trisha the Severe Hottie (Member # 6000) on :
You can send it to me I think my address is in my profile.
Posted by Shigosei (Member # 3831) on :
Oregon State has this really cool program where undergraduate students can get grants to do research. It's funded by the Howard Hughes Medical Institute (yeah, the guy who made the Spruce Goose). Anyhow, the paper on the project I've been working on should come out in a few months--it's being reviewed now. If it's in a journal that publishes on the web, I'll try to have a link for all of you. I'm so excited about it!
Posted by rivka (Member # 4859) on :
Wow! That is so great!
And to think, we can say we knew you when! Posted by Shigosei (Member # 3831) on :
Dad was just talking tonight about how someday at my high school they're going to point out the yearbook I worked on and say, "That yearbook was edited by Dr. Shigosei, who developed the first permanent artificial heart." He then speculated on what local places would be named after me. O_O
Trust me, when you say you knew me when, no one will know what you're talking about
![[Grumble]](graemlins/grumble.gif)
. But afterward, he told me I had given the best explanation of X-ray crystallography that he had ever seen from an undergrad/high school student (I started working in this lab as a junior in high school). The professor was also pleased with my presentation. If anyone wants to see the power point I used, I'll be happy to e-mail it to them.
![[Big Grin]](biggrin.gif)
![[Smile]](smile.gif)
I think my address is in my profile.
![[Wink]](wink.gif)