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Tuberculosis Protein: Key to Understanding 'Gene Switch' Video Description for the Visually Impaired

Tuberculosis Protein: Key to Understanding 'Gene Switch' Video Description for the Visually Impaired (back to video)

Visual:

Over images of tuberculosis bacteria and the tuberculosis cyclic AMP receptor (CRP) protein is text that reads "Tuberculosis Protein: Key to Understanding 'Gene Switch'"

Visual:

NIST biochemist Travis Gallagher next to computer monitor showing rotating structure of the tuberculosis CRP.

Text at bottom of screen reads "Travis Gallagher, Biochemist, National Institute of Standards and Technology"

"What we're seeing here is the three-dimensional structure of a cyclic AMP receptor protein.  This is a protein found in many pathogenic bacteria ..."

Visual:

Close up view of rotating CRP.

Gallagher:

"... and the protein we're seeing right now is from the microbe that causes tuberculosis. Now this protein is made of two subunits shown here in purple and green, and they're genetically identical. "

Visual:

As CRP continues to rotate, text enters screen that reads "CRP, Cyclic AMP Receptor Protein."

Gallagher:

"The protein is called CRP for Cyclic AMP Receptor Protein ..."

Visual:

Image of CRP on computer monitor showing cyclic AMP molecules in yellow within the protein.

Gallagher:

"... because it binds the small molecule called Cyclic AMP shown here in yellow. "

Visual:

Close up of CRP on computer monitor as Gallagher's finger points to yellow cyclic AMP molecules within the protein.

Gallagher:

"And that's a signal that is telling the protein to switch on ..."

Visual:

Gallagher next to computer monitor with image of rotating CRP.

Gallagher:

"... so that it can switch on genes that the bacterium needs to survive."

Visual:

Rotating image of CRP.

Gallagher:

"In most cases of proteins with two subunits, they're going to have the same exact shape.However, what we got as a surprise when we saw the structure was that they're not symmetric—there's an asymmetry here ..."

Visual:

Image of CRP with asymmetrical regions at top of protein highlighted in white.  Gallagher's finger enters scene and points to white regions.

Gallagher:

"... and the asymmetric parts are mostly in the top of the protein shown here in white.  This is the part that binds DNA." 

Visual:

Gallagher next to computer monitor with image of rotating CRP.

Gallagher:

What we think is going on here is that the protein ..."

Visual:

Image of CRP with white asymmetric regions at top of protein.  Text at top reads "Asymmetric 'OFF' State."

Gallagher:

"...  is switching from off to on by going from this asymmetric state ..."

Visual:

Image changes from CRP in "off" state (with white asymmetric regions at top) to image of CRP in "on" state (with white regions removed and yellow cyclic AMP molecules inserted into the protein).

Gallagher:

"...  to a symmetric state and that's what Cyclic AMP triggers it to do."

Visual:

Image of rotating CRP.

Gallagher:

"The next step will be to try to get the protein in both states from the same microbe. So our tuberculosis protein..."

Visual:

Gallagher next to computer monitor with image of rotating CRP.

Gallagher:

"...  that we've just used to solve the off state— we want to get this one in the on state, too.  And then we can see the very same protein from the same organism in both on and off states ..."

Visual:

Image of rotating CRP.

Gallagher:

"... and that will give us the best chance to really see how it switches and understand the mechanism. So it's a scientific advance ..."

Visual:

Gallagher next to computer monitor with image of rotating CRP.

Gallagher:

"... and we can use this knowledge to develop strategies to fight tuberculosis and other pathogenic microbes."

Visual:

Text on black screen reads "For more information on this research, go to http://www.nist.gov/public_affairs/releases/tuberculosis.html."

Visual:

Text on black screen reads "Produced by National Institute of Standards and Technology Public Affairs Office, February 2009."

Created February 3, 2010, Updated January 3, 2017