[ramraj07]

??? Unless you jump from eukaryotes to archea these are not real concerns. Most PTM markers are very conserved.

[Ovah]

I'd say the jump from eukaryotes to procaryotes is a realistic scenario in recombinant DNA technology.

I have some experience with recombinant yeast and PTMs. Degree of glycosylation actually vary a lot depending on strain used and has a huge effect of protein activity. And of course these PTMs affects the crystal structure.