Introduction Elements of Protein Engineering

analysis of the primary structure (amino acid sequence)  

determination and isolation of the corresponding gene (steps 2 and 3 are reversed, if the protein is searched for on the DNA level) (see Chapter 4)  

crystallization of the homogeneous protein (this can be done parallel to steps 2 and 3, but more often requires step 3 to achieve large amounts of pure recombinant protein), 

X-ray analysis of the protein crystals (sometimes NMR of the protein in solution is sufficient, depending on the size of the protein)  

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