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Nathan Haskins
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Nathan Haskins
Get this done..
-roys letter…
-http://www.uri.edu/ois/sta/STA_sub/sta_app.htm
-remove blog password
-just have the acetyle model attached to the end of the tail
-tell jon and nick to see dr. cho to talk about progresss….
-model acetyle group
-send script to dr. cho email. -
Nathan Haskins
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Nathan Haskins
Supercoils: Reference Images
There are two types of supercoiling:
- 1. Plectonemic supercoils (“unrestrained”). The DNA in the above electron micrograph is said to be plectonemically supercoiled.
Characteristics of plectonemically supercoiled DNA (“unrestrained”)- a. frequently branched
b. Wr/DTw is constant and about 3
c. length is independent of s and is ~40% ofthe couture length.
d. the superhelix diameter varies with s at “physiological levels” of s, the superhelixaxis is extremely sensitive to small changesin supercoiling.
e. the number of supercoils is directly proportionalto |s| and is Å 0.9DLkTwo other (theoretical, not (yet) verified experimentally) properties:
f. supercoiling increases the local concentration of two DNA sites in a DNA molecule by ~100x
g. branching of the superhelix is enthalpically unfavourable but is driven by entropy.
2.Toroidal supercoils (“restrained” by proteins)
Characteristics of Toroidal supercoils:
- a. compact (ratio is ~10x).
b. writhe and twist may vary, e.g., they’re not “linked”.
c. length becomes shorter with more turns.
d. usually involved with proteins – often wrapping.
NOTE THAT the plectonemic & torroidal molecules are drawn to scale – that is, the torroidal supercoiling is much more efficient at compacting the DNA.
Inside a bacterial cell, both types of supercoiling are present.
We have done experiments to measure unrestrained supercoiling in plasmid DNA (small circles of about 3000 bp), and have found that very close to half of the supercoils are constraned by proteins in vivo. A cartoon of a the distribution of supercoiling in a 3000 bp plasmid is shown below. If you were to strip off all of the proteins, and measure the supercoiling, there would be 20 supercoils in this plasmid. Most DNA isolated from E.coli has roughly this level of supercoiling.
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Nathan Haskins
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Nathan Haskins
Work due for 3/5/07
I want to have models ready for review on the following…
Items to Model for movie..-Histones
-1, 2a, 2b, 3, 4
-histone tails
-acetyle groups
-lysome docking spot-DNa strand
-HDAC
-The drug
-Chromosomes
-supercoil strands————————————-
If there is time, which i doubt, I want to have some work on these elements ready to go as well…Backdrops…
-Chromo level
-inside the cromo
-super coil level
-histone level
-nondiegetic insert
-backdrop for intro/outtro text -
Nathan Haskins
Programs that automate slides shows for web.
Adobe might have ben inspired to make their software, Lightbox, after seeing how awesome Swishzone’s SwishPix applet works… lets have a look..
Above: The Lightbox interface is very clean, and allows for some photo manipulation of values and red eye removal. Once the photos are preped, they can be named, commented, and published to web automatically with a push of a button. Just choose a template and go.
Lightbox can be download for a free trail at: http://www.adobe.com
Above: The original gangsta of automated web photogalleries flash style, SwishPix is a lot more compact then Lightbox. The interface is very streamline, tabbed style, and it makes getting your photos to the web, or CD mailer easy. The interface is not as fancy, and it has limited color correction capabilities. However, what it lacks in features it makes up for in speed and price point. SwishPix is under $50.00 and does the same thing as Lightbox.
SwishPix can be found at Swishzone: http://www.swishzone.com
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Nathan Haskins
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Nathan Haskins
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Nathan Haskins
