6erj | pdb_00006erj

Self-complemented FimA subunit from Salmonella enterica

spinqualitylabelsall models 6erj, resolution 1.69Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6erj is a 2 chain structure with sequence from Salmonella enterica subsp. enterica serovar Paratyphi A str. ATCC 9150. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.69Å Ligands: ACY Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A0H2WR29_SALPA Publication Abstract from PubMed Adhesive type 1 pili from enteroinvasive, Gram-negative bacteria mediate attachment to host cells. Up to 3000 copies of the main pilus subunit, FimA, assemble into the filamentous, helical quaternary structure of the pilus rod via a mechanism termed donor-strand complementation, in which the N-terminal extension of each subunit, the donor strand, is inserted into the incomplete immunoglobulin-like fold of the preceding FimA subunit. For FimA from Escherichia coli, it has been previously shown that the protein can also adopt a monomeric, self-complemented conformation in which the donor strand is inserted intramolecularly in the opposite orientation relative to that observed for FimA polymers. Notably, soluble FimA monomers can act as apoptosis inhibitors in epithelial cells after uptake of type 1-piliated pathogens. Here, we show that the FimA orthologues from E. coli, Shigella flexneri, and Salmonella enterica can all fold to form self-complemented monomers. We solved X-ray structures of all three FimA monomers at 0.89-1.69 A resolutions, revealing identical, intramolecular donor-strand complementation mechanisms. Our results also showed that the pseudo-palindromic sequences of the donor strands in all FimA proteins permit their alternative folding possibilities. All FimA monomers proved to be 5060 kJ/mol less stable against unfolding than their pilus rod-like counterparts (which exhibited very high energy barriers of unfolding and refolding). We conclude that the ability of FimA to adopt an alternative, monomeric state with anti-apoptotic activity is a general feature of FimA proteins of type 1-piliated bacteria. Alternative folding to a monomer or homopolymer is a common feature of the type 1 pilus subunit FimA from enteroinvasive bacteria.,Zyla DS, Prota AE, Capitani G, Glockshuber R J Biol Chem. 2019 May 24. pii: RA119.008610. doi: 10.1074/jbc.RA119.008610. PMID:31126987 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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