Table 2. Structural comparison between different phosphorylation states.

State	WT	p53 15pSer	p53 18pThr	p53 20pSer
Arg1731	Interacts with Glu11	Interacts with Glu11	Interacts with Thp18	Interacts with Asp21
Arg1732	Interacts with TAZ2 Asp1729	Interacts with TAZ2 Asp1729	Interacts with TAZ2 Asp1729	Interacts with TAZ2 Asp1729
Arg1737	Interacts with Phe19	Interacts with Sep15	Interacts with Thp18	Transient salt bridges with N-terminal acidic residues
p53 Leu22	Inside a hydrophobic pocket formed by helix α1, α2 and α3. Interacts with p53 Leu25.	Inside a hydrophobic pocket between helix α3 and α2. Interacts with p53 Leu25.	Inside a hydrophobic pocket between helix α3 and α2. Interacts with p53 Leu25.	Inside a hydrophobic pocket between helix α3 and α2. Interacts with p53 Phe19 and Leu25.
p53 Phe19	Arg1737 and Met1761.	Inside a hydrophobic pocket formed by helix α1 and α2	Inside a hydrophobic pocket formed by helix α1 and α2. Higher SASA than WT.	Exposed to solvent and interacts with p53 Leu22.
p53 phosphorylated residue		Interacts with Arg1737.	Interacts with Arg1731, Arg1737. H-bond with its own amide backbones and those of p53 Glu17.	Interacts with Lys24.
Extension of the p53 helix	15–22	16–21	16–20	19–22