6lf3

3D domain-swapped dimer of the maltose-binding protein fused to a fragment of the protein-tyrosine kinase 2-beta

spinqualitylabelsall models 6lf3, resolution 3.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6lf3 is a 6 chain structure with sequence from Escherichia coli K-12 and Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.2Å Ligands: GLC, PRD_900001 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease FAK2_HUMAN Note=Aberrant PTK2B/PYK2 expression may play a role in cancer cell proliferation, migration and invasion, in tumor formation and metastasis. Elevated PTK2B/PYK2 expression is seen in gliomas, hepatocellular carcinoma, lung cancer and breast cancer. Function MALE_ECOLI Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides.FAK2_HUMAN Non-receptor protein-tyrosine kinase that regulates reorganization of the actin cytoskeleton, cell polarization, cell migration, adhesion, spreading and bone remodeling. Plays a role in the regulation of the humoral immune response, and is required for normal levels of marginal B-cells in the spleen and normal migration of splenic B-cells. Required for normal macrophage polarization and migration towards sites of inflammation. Regulates cytoskeleton rearrangement and cell spreading in T-cells, and contributes to the regulation of T-cell responses. Promotes osteoclastic bone resorption; this requires both PTK2B/PYK2 and SRC. May inhibit differentiation and activity of osteoprogenitor cells. Functions in signaling downstream of integrin and collagen receptors, immune receptors, G-protein coupled receptors (GPCR), cytokine, chemokine and growth factor receptors, and mediates responses to cellular stress. Forms multisubunit signaling complexes with SRC and SRC family members upon activation; this leads to the phosphorylation of additional tyrosine residues, creating binding sites for scaffold proteins, effectors and substrates. Regulates numerous signaling pathways. Promotes activation of phosphatidylinositol 3-kinase and of the AKT1 signaling cascade. Promotes activation of NOS3. Regulates production of the cellular messenger cGMP. Promotes activation of the MAP kinase signaling cascade, including activation of MAPK1/ERK2, MAPK3/ERK1 and MAPK8/JNK1. Promotes activation of Rho family GTPases, such as RHOA and RAC1. Recruits the ubiquitin ligase MDM2 to P53/TP53 in the nucleus, and thereby regulates P53/TP53 activity, P53/TP53 ubiquitination and proteasomal degradation. Acts as a scaffold, binding to both PDPK1 and SRC, thereby allowing SRC to phosphorylate PDPK1 at 'Tyr-9, 'Tyr-373', and 'Tyr-376'. Promotes phosphorylation of NMDA receptors by SRC family members, and thereby contributes to the regulation of NMDA receptor ion channel activity and intracellular Ca(2+) levels. May also regulate potassium ion transport by phosphorylation of potassium channel subunits. Phosphorylates SRC; this increases SRC kinase activity. Phosphorylates ASAP1, NPHP1, KCNA2 and SHC1. Promotes phosphorylation of ASAP2, RHOU and PXN; this requires both SRC and PTK2/PYK2. Publication Abstract from PubMed The maltose-binding protein (MBP) is one of the most frequently used protein tags due to its capacity to stabilize, solubilize and even crystallize recombinant proteins that are fused to it. Given that MBP is thought to be a highly stable monomeric protein with known characteristics, fused passenger proteins are often studied without being cleaved from MBP. Here we report that a commonly used engineered MBP version (mutated to lower its surface entropy) can form interlaced dimers when fused to short protein sequences derived from the focal adhesion kinase (FAK) or the homologous protein tyrosine kinase 2 (PYK2). These MBP dimers still bind maltose and can interconvert with monomeric forms in vitro under standard conditions despite a contact surface of more than 11,000 A(2). We demonstrate that both the mutations in MBP and the fused protein sequences were required for dimer formation. The FAK and PYK2 sequences are less than 40% identical, monomeric, and did not show specific interactions with MBP, suggesting that a variety of sequences can promote this MBP dimerization. MBP dimerization was abrogated by reverting two of the eight mutations introduced in the engineered MBP. Our results provide an extreme example for induced reversible domain-swapping, with implications for protein folding dynamics. Our observations caution that passenger-promoted MBP dimerization might mislead experimental characterization of the fused protein sequences, but also suggest a simple mutation to stop this phenomenon. Passenger sequences can promote interlaced dimers in a common variant of the maltose-binding protein.,Momin AA, Hameed UFS, Arold ST Sci Rep. 2019 Dec 31;9(1):20396. doi: 10.1038/s41598-019-56718-y. PMID:31892719 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Maltose-binding protein 3D structures

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