| The N-terminal ligation precursor |
| Primarily determines the ligation efficiency |
| Is most efficient when slowly hydrolyzed by the proteasome and therefore possesses a longer half-life |
| Is most efficient when there is a negatively charged or polar residue at P1 combined with a small or polar residue at P2
|
| Can participate in ligation if a hydrophobic residues at P1 is combined with a basic, small, or—to a lesser extent—polar or negatively charged residue at P2
|
| The C-terminal ligation partner |
| Has less stringent structural requirements, although not all fragments are suitable ligation partners |
| Influences the ligation efficiency more through its mere presence and concentration than by its precise sequence. |
|
Cis-splicing or random recombination? |
| Splicing from short peptides occurs both through cis-splicing and via random recombination |
| Splicing from longer precursor peptides is non-random and occurs predominantly via cis-splicing, especially at lower precursor peptide concentrations |
