What happens to proteins under x ray/gamma ray radiation? A simple question to which I am yet to find an answer. I have not found any papers which would go into detail about it, there is some stuff on protein damage in x-ray crystallography but they are looking at the crystallized proteins, I am interested in "natural" proteins...
 A: X-ray and gamma rays do cause damage do the proteins, however it is important to notice that they are different things and the chemical mechanisms for causing damage to proteins are usually different, although both end up causing damage by ionization processes.
About x-rays
The damage of x-rays in proteins is relevant in the context of cristallography:

The majority of 3D structures of macromolecules are currently
  determined by macromolecular crystallography, which employs the
  diffraction of X-rays on single crystals. However, during diffraction
  experiments, the X-rays can damage the protein crystals by ionization
  processes, especially when powerful X-ray sources at synchrotron
  facilities are used. This process of radiation damage generates
  photo-electrons that can get trapped in protein moieties. The 3D
  structure derived from such experiments can differ remarkably from the
  structure of the native molecule.[1]

This is a problem because bigger proteins need more powerful X-ray sources for higher resolution of the crystal structure, which however causes more damage to the protein. To alleviate the problem, the samples are kept at cryogenic temperatures, but this does not solve the problem completely. For this reasons it is important to analyse different crystals and use other techniques that can provide redundant information about tertiary structure of proteins for confirmation such as NMR (Nuclear magnetic resonance spectroscopy). 
About gamma rays
Gamma rays, on the other hand, usually affect proteins on contexts like radioactive exposure (in space or contact with radioactive sources).

High-energy electrons and gamma rays ionize molecules at random along
  their trajectories. In each event, chemical bonds are ruptured,
  releasing radiolytic products that diffuse away. A solution of
  macromolecules is mostly water whose principal radiation products are
  H(+) and OH(-). These can diffuse to and react with macromolecules;
  this indirect action of radiation is responsible for 99.9% of the
  damage to proteins.[2]

This is not necessarily bad as gamma rays are commonly used for desinfection [3]. However, it is a big concern for astronauts and during radioactive incidents.
[1] Carugo, Oliviero, and Kristina Djinović Carugo. "When X-rays modify the protein structure: radiation damage at work." Trends in biochemical sciences 30.4 (2005): 213-219.
[2] Kempner, E. S. "Effects of high‐energy electrons and gamma rays directly on protein molecules." Journal of pharmaceutical sciences 90.10 (2001): 1637-1646.
[3] Ridenour, Gerald M., and Edward H. Armbruster. "Effect of high-level gamma radiation on disinfection of water and sewage." Journal (American Water Works Association) 48.6 (1956): 671-676.
