Molecular Mechanism of the Pin1-Histone H1 Interaction.

Pin1 is an essential peptidyl-prolyl isomerase (PPIase) that catalyzes cis-trans prolyl isomerization in proteins containing pSer/Thr-Pro motifs. It has an N-terminal WW domain that targets these motifs and a C-terminal PPIase domain that catalyzes isomerization. Recently, Pin1 was shown to modify the conformation of phosphorylated histone H1 and stabilize the chromatin-H1 interaction by increasing its residence time.