5fhy
From Proteopedia
Crystal structure of FliD (HAP2) from Pseudomonas aeruginosa PAO1
Structural highlights
Function[FLID2_PSEAE] Required for the morphogenesis and for the elongation of the flagellar filament by facilitating polymerization of the flagellin monomers at the tip of growing filament. Forms a capping structure, which prevents flagellin subunits (transported through the central channel of the flagellum) from leaking out without polymerization at the distal end. Essential for motility. Responsible for adhesion to mucin, which is the initial event in colonization by this organism of the airways of cystic fibrosis patients. Publication Abstract from PubMedFlagella are critical for bacterial motility and pathogenesis. The flagellar capping protein (FliD) regulates filament assembly by chaperoning and sorting flagellin (FliC) proteins after they traverse the hollow filament and exit the growing flagellum tip. In the absence of FliD, flagella are not formed resulting in impaired motility and infectivity. Here, we report the 2.2 A resolution X-ray crystal structure of FliD from Pseudomonas aeruginosa, the first high-resolution structure of any FliD protein from any bacterium. In combination with a multitude of biophysical and functional analyses, we find that Pseudomonas FliD exhibits unexpected structural similarity to other flagellar proteins at the domain level, adopts a unique hexameric oligomeric state, and depends on flexible determinants for oligomerization. Considering that the flagellin filaments on which FliD oligomers are affixed vary between bacteria in protofilament number, our results suggest that FliD oligomer stoichiometries vary across bacteria to complement their filament assemblies. Bacterial flagellar capping proteins adopt diverse oligomeric states.,Postel S, Deredge D, Bonsor DA, Yu X, Diederichs K, Helmsing S, Vromen A, Friedler A, Hust M, Egelman EH, Beckett D, Wintrode PL, Sundberg EJ Elife. 2016 Sep 24;5. pii: e18857. doi: 10.7554/eLife.18857. PMID:27664419[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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