Crystal structure of the MAP kinase binding domain and the catalytic domain of human MKP5

Abstract

MAP kinase phosphatases (MKPs) have crucial roles in regulating the signaling activity of MAP kinases and are potential targets for drug discovery against human diseases. These enzymes contain a catalytic domain (CD) as well as a binding domain (BD) that help recognize the target MAP kinase. We report here the crystal structures at up to 2.2 Å resolution of the BD and CD of human MKP5 and compare them to the known structures from other MKPs. Dramatic structural differences are observed between the BD of MKP5 and that of MKP3 determined previously by NMR. In particular, the cluster of positively charged residues that is important for MAP kinase binding is located in completely different positions in the two structures, with a distance of 25 Å between them. Moreover, this cluster is a-helical in MKP5, while it forms a loop followed by a b-strand in MKP3. These large structural differences could be associated with the distinct substrate preferences of these phosphatases, but further studies are needed to confirm this. The CD of MKP5 is observed in an active conformation, and two loops in the active site have backbone shifts of up to 5 Å relative to the inactive CDs from other MKPs.

Molecular basis of MAP kinase regulation

“…The MKBDs of DUSP6/MKP3 (NMR spectroscopy), DUSP10/MKP5 (X‐ray crystallography) and DUSP16/MKP7 (X‐ray crystallography) have been structurally characterized. All adopt a common mixed α/β‐fold that is highly similar to that of sulfurtransferases (rhodaneses) and the DUSP Cdc25A.…”

Protein tyrosine phosphatases: dual‐specificity phosphatases in health and disease

“…In vitro substrates are p38 and JNK, but not ERK [72]. This MKP contains a 150‐amino acid N‐terminal MAPK‐binding domain [73] that binds to p38 and is required for efficient p38 dephosphorylation, followed by two CDC25‐like domains. Unlike many other DSPs, MKP‐5 assumes a configuration that predicts constitutive enzymatic activity [74].…”

Structural Basis for the Regulation of the Mitogen-activated Protein (MAP) Kinase p38α by the Dual Specificity Phosphatase 16 MAP Kinase Binding Domain in Solution

“…In contrast, far fewer MKBDs have been structurally investigated. Moreover, despite the small sample size, the three-dimensional structures of the MKBDs from DUSP6 (MKP-3) (21), DUSP10 (MKP-5) (22), and DUSP16 (MKP-7) (23) are quite different. This raises the possibility that the differences in their structures may contribute to their differential selectivity and activity toward different MAPKs.…”