HOMEWORK#3

 

  • due on 11/11

Average images from GroEL side views in the absence orpresence of ADP and GroES.

Escherichia coli GroEL and GroES are the prototypical chaperonin and co-chaperonin. Chaperonins are ring-shaped molecular chaperone proteins that are found in all organisms and are essential for protein folding and protection from stress. Both the chaperonin and co-chaperonin are 7-fold symmetric oligomers. GroEL is composed of fourteen identical 60 kDa subunits arranged in two stacked rings, and GroES is composed of a seven identical 10 kDa subunits.

1. Show the crystal structure of a single GroES subunit.

2. Show the crystal structure of a single GroEL subunit.

3. Show "top view" C-alpha trace colored by chain of GroEL and measure the width of its central cavities.

4. Show "side view" cartoon display colored by structure of GroES and measure its width.

5. Estimate the central cavities' width of GroEL from image shown above. Compare this width with the one you measured from crystal structure.