2j4o
STRUCTURE OF TAB1
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OverviewOverview
TAB1 [TAK1 (transforming growth factor-beta-activated kinase 1)-binding, protein 1] is one of the regulatory subunits of TAK1, a protein kinase, that lies at the head of three pro-inflammatory kinase cascades. In the, current study we report the crystal structure of the N-terminal domain of, TAB1. Surprisingly, TAB1 possesses a fold closely related to that of the, PPM (Mg2+- or Mn2+-dependent protein phosphatase) family as demonstrated, by the close structural similarity with protein phosphatase 2C alpha., However, we were unable to detect any phosphatase activity for TAB1 using, a phosphopeptide or p-nitrophenyl phosphate as substrate. Although the, overall protein phosphatase 2C alpha fold is conserved in TAB1, detailed, structural analyses and mutagenesis studies show that several key residues, required for dual metal-binding and catalysis are not present in TAB1, although binding of a single metal is supported by soaking experiments, with manganese and isothermal titration calorimetry. Thus, it appears that, TAB1 is a 'pseudophosphatase', possibly binding to and regulating, accessibility of phosphorylated residues on substrates downstream of TAK1, or on the TAK1 complex itself.
About this StructureAbout this Structure
2J4O is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
TAK1-binding protein 1 is a pseudophosphatase., Conner SH, Kular G, Peggie M, Shepherd S, Schuttelkopf AW, Cohen P, Van Aalten DM, Biochem J. 2006 Nov 1;399(3):427-34. PMID:16879102
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