dual specificity phosphatase domain of plant IBR5-like protein phosphatases
This subfamily is composed of Arabidopsis thaliana INDOLE-3-BUTYRIC ACID (IBA) RESPONSE 5 (IBR5) and similar plant proteins. IBR5 protein is also called SKP1-interacting partner 33. The IBR5 gene encodes a dual-specificity phosphatase (DUSP) which acts as a positive regulator of plant responses to auxin and abscisic acid. DUSPs function as protein-serine/threonine phosphatases (EC 3.1.3.16) and protein-tyrosine-phosphatases (EC 3.1.3.48). Typical DUSPs, also called mitogen-activated protein kinase (MAPK) phosphatases (MKPs), deactivate MAPKs by dephosphorylating the threonine and tyrosine residues in the conserved Thr-Xaa-Tyr motif residing in their activation sites. IBR5 is an atypical DUSP; it contains the catalytic dual specificity phosphatase domain but lacks the N-terminal Cdc25/rhodanese-like domain that is present in typical DUSPs. It has been shown to target MPK12, which is a negative regulator of auxin signaling.
Feature 1: catalytic site [active site], 2 residue positions
Conserved feature residue pattern:C R
Evidence:
Comment:the catalytic cysteine initiates a nucleophilic attack on the phosphate group of the substrate, forming a transient phosphoenzyme intermediate and releasing the substrate dephosphorylated; the transition state is stabilized by the arginine present in the catalytic pocket
Jiyao W et al.(2023). "The conserved domain database in 2023.",