6WLX

PAK4 kinase domain in complex with beta-catenin Ser675 substrate peptide

6WLX の概要

• エントリーDOI: 10.2210/pdb6wlx/pdb
• 分子名称: Serine/threonine-protein kinase PAK 4, Catenin beta-1 (3 entities in total)
• 機能のキーワード: serine/threonine kinase pak4, beta-catenin, phosphopeptide, ser675, transferase
• 由来する生物種: Homo sapiens (Human); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 39985.18

構造登録者

Chetty, A.K.,Ha, B.H.,Boggon, T.J. (登録日: 2020-04-20, 公開日: 2020-06-24, 最終更新日: 2024-10-30)

主引用文献

Chetty, A.K.,Sexton, J.A.,Ha, B.H.,Turk, B.E.,Boggon, T.J.
Recognition of physiological phosphorylation sites by p21-activated kinase 4.
J.Struct.Biol., 211:107553-107553, 2020

PubMed Abstract: Many serine/threonine protein kinases discriminate between serine and threonine substrates as a filter to control signaling output. Among these, the p21-activated kinase (PAK) group strongly favors phosphorylation of Ser over Thr residues. PAK4, a group II PAK, almost exclusively phosphorylates its substrates on serine residues. The only well documented exception is LIM domain kinase 1 (LIMK1), which is phosphorylated on an activation loop threonine (Thr508) to promote its catalytic activity. To understand the molecular and kinetic basis for PAK4 substrate selectivity we compared its mode of recognition of LIMK1 (Thr508) with that of a known serine substrate, β-catenin (Ser675). We determined X-ray crystal structures of PAK4 in complex with synthetic peptides corresponding to its phosphorylation sites in LIMK1 and β-catenin to 1.9 Å and 2.2 Å resolution, respectively. We found that the PAK4 DFG + 1 residue, a key determinant of phosphoacceptor preference, adopts a sub-optimal orientation when bound to LIMK1 compared to β-catenin. In peptide kinase activity assays, we find that phosphoacceptor identity impacts catalytic efficiency but does not affect the K value for both phosphorylation sites. Although catalytic efficiency of wild-type LIMK1 and β-catenin are equivalent, T508S mutation of LIMK1 creates a highly efficient substrate. These results suggest suboptimal phosphorylation of LIMK1 as a mechanism for controlling the dynamics of substrate phosphorylation by PAK4.

PubMed: 32585314
DOI: 10.1016/j.jsb.2020.107553

実験手法

X-RAY DIFFRACTION (2.2 Å)