Before revision:  To date , there is little molecular structural data available  on the AGAAAAGA palindrome in the hydrophobic region ( 113-120 ) of prion proteins .This region belongs to the N-terminal unstructured region ( 1-123 ) of prion proteins , the structure of which has proved hard to determine using NMR spectroscopy or X-ray crystallography due to the insoluble and noncrystalline nature of the amyloid fibril .
After revision:  To date , there is little molecular structural data available on the AGAAAAGA palindrome in the hydrophobic region ( 113-120 ) of prion proteins , which falls just within the N-terminal unstructured region ( 1-123 ) of prion proteins , the structure of which has proved hard to determine using NMR spectroscopy or X-ray crystallography due to the insoluble and noncrystalline nature of the amyloid fibril .