Global Protein Structure Issues
  1. How are 3D macromolecular structures obtained?
    1. Accurate: 83% by X-ray crystallography, 15% by NMR
    2. Rough: Homology modeling, but templates available for only ~20% of cases.
    3. Ab initio theory does not predict tertiary structure accurately enough for most purposes.

  2. What percentage of the human proteome has known structure?
    1. ~1% accurately (empirical).
    2. ~10% roughly (homology modeling).
    3. Solution: Structural Genomics? (Not in the next few years.)

  3. Some proteins are intrinsically unstructured to support their functions.
    1. ~10% of proteins are predicted to be fully disordered.
      Examples (bound to structured proteins): 1JSU, 1G3J, 1OCT (Tompa, 2002).
    2. ~40% of eukaryotic proteins have at least one long (>50 residues) disordered region.

by Eric Martz, University of Massachusetts, July 2003 (revised February 2004)