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-helices are magenta-colored spirals; 
-strands are yellow-colored arrows (pointing from the N to C terminus); regular turns are colored light blue; and unspecified (mostly connecting) segments are colored white.
The first quiz requires that you identify seven basic elements of protein architecture on cartoon diagrams of protein G; the coloring used is RasMol "Structure". The elements to be identified are provided in the following order:
-hairpin motif.
-helix.
-helical dipole.
-strands.
This quiz depicts protein G in several of the RasMol display and coloring formats. In order to click on the features of these images correctly, you may want to have protein G displayed in a separate browser window (see below). As in the Overall Architecture quiz, a click on the correct portion of each image will take you to the next page.
This quiz is similar to the second in format with an additional emphasis on amino acid side chains and tertiary structure.
Start the quiz on Tertiary Structure & Sidechains.
An active Chime display of the Protein G structure can be viewed in a separate Netscape window by clicking on the above link. You will need the Chemscape Chime plug-in to view this pop-up page.
You can return to this Protein Structure Quiz Introduction from all of the question pages by selecting the link after scrolling in the Menu frame above.
A "Scoreboard" with the number of questions tried and incorrect clicks made during the quiz can also be seen in the Menu frame.
Protein G is a multidomain extracellular protein found in several Streptococcal species. The "protein G" referred to in this quiz is actually only the B1 domain of one of these proteins. These repeated domains bind to the Fc portion of IgG. There is no structural similarity between these domains and the StrepA protein, which has similar binding properties. Additional information on the B domains of protein G can be found in the following articles:
Structure Determination.
Gallagher, T. et al. (1994) "Two crystal structures of the B1 immunoglobulin-binding domain of Streptococcal protein G and comparison with NMR." Biochemistry 33, 4721.
Gronenborn, A. M. et al. (1991) "A novel, highly stable fold of the immunoglobulin binding domain of Streptococcal protein G." Science 253, 657.
Protein Folding Energetics.
Alexander, P. et al. (1992) "Thermodynamic analysis of the folding of the Streptococcal Protein G IgG-binding Domains B1 and B2: Why small proteins tend to have high denaturation temperatures" Biochemistry
31, 3597.
Minor, D. L. & Kim, P. S. (1994) "Measurement of the
Smith, C. K. et al. (1994) "A thermodynamic scale for the
Smith, C. K. & Regan, L. (1995) "Guidelines for protein design: The energetics of
Minor, D. L. & Kim, P. S. (1996) "Context-dependent secondary structure formation of a designed protein sequence." Nature 380, 730.
Dalal, S., Balasubramanian, S., & Regan, L. (1997) "Protein Alchemy: Changing
William McClure
Last modified August 11, 1997
In addition, since this quiz was designed to be somewhat more challenging, specific hints are given and the option to skip to the next question is provided following each incorrect answer. Hints and comments also appear sometimes in the window status bar.
Start the quiz on Secondary Structure.
-sheet-forming propensities of amino acids." Nature 367, 660.
-sheet forming tendencies of the amino acids." Biochemistry 33, 5510.
-sheet side chain interactions." Science 270, 980.
-sheet into -helix." Nature Struct. Biol. 4, 548.
Back to Molecular Models for Biochemistry at CMU.
wm0p@andrew.cmu.edu.
Department of Biological Sciences
Carnegie Mellon University
Pittsburgh, PA 15213
