2hw6
Crystal structure of Mnk1 catalytic domainCrystal structure of Mnk1 catalytic domain
Structural highlights
FunctionMKNK1_HUMAN May play a role in the response to environmental stress and cytokines. Appears to regulate translation by phosphorylating EIF4E, thus increasing the affinity of this protein for the 7-methylguanosine-containing mRNA cap.[1] [2] [3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAutoinhibition is a recurring mode of protein kinase regulation and can be based on diverse molecular mechanisms. Here, we show by crystal structure analysis, nuclear magnetic resonance (NMR)-based nucleotide affinity studies and rational mutagenesis that nonphosphorylated mitogen-activated protein (MAP) kinases interacting kinase (Mnk) 1 is autoinhibited by conversion of the activation segment into an autoinhibitory module. In a Mnk1 crystal structure, the activation segment is repositioned via a Mnk-specific sequence insertion at the N-terminal lobe with the following consequences: (i) the peptide substrate binding site is deconstructed, (ii) the interlobal cleft is narrowed, (iii) an essential Lys-Glu pair is disrupted and (iv) the magnesium-binding loop is locked into an ATP-competitive conformation. Consistently, deletion of the Mnk-specific insertion or removal of a conserved phenylalanine side chain, which induces a blockade of the ATP pocket, increase the ATP affinity of Mnk1. Structural rearrangements required for the activation of Mnks are apparent from the cocrystal structure of a Mnk2 D228G -staurosporine complex and can be modeled on the basis of crystal packing interactions. Our data suggest a novel regulatory mechanism specific for the Mnk subfamily. Mitogen-activated protein kinases interacting kinases are autoinhibited by a reprogrammed activation segment.,Jauch R, Cho MK, Jakel S, Netter C, Schreiter K, Aicher B, Zweckstetter M, Jackle H, Wahl MC EMBO J. 2006 Sep 6;25(17):4020-32. Epub 2006 Aug 17. PMID:16917500[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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