3j9q

Atomic structures of a bactericidal contractile nanotube in its pre- and post-contraction statesAtomic structures of a bactericidal contractile nanotube in its pre- and post-contraction states

3j9q, resolution 3.50Å Show:Asymmetric Unit Biological Assembly Structural highlights 3j9q is a 48 chain structure with sequence from Pseudomonas aeruginosa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 3j9r Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed R-type pyocins are representatives of contractile ejection systems, a class of biological nanomachines that includes, among others, the bacterial type VI secretion system (T6SS) and contractile bacteriophage tails. We report atomic models of the Pseudomonas aeruginosa precontraction pyocin sheath and tube, and the postcontraction sheath, obtained by cryo-EM at 3.5-A and 3.9-A resolutions, respectively. The central channel of the tube is negatively charged, in contrast to the neutral and positive counterparts in T6SSs and phage tails. The sheath is interwoven by long N- and C-terminal extension arms emanating from each subunit, which create an extensive two-dimensional mesh that has the same connectivity in the extended and contracted state of the sheath. We propose that the contraction process draws energy from electrostatic and shape complementarities to insert the inner tube through bacterial cell membranes to eventually kill the bacteria. Atomic structures of a bactericidal contractile nanotube in its pre- and postcontraction states.,Ge P, Scholl D, Leiman PG, Yu X, Miller JF, Zhou ZH Nat Struct Mol Biol. 2015 Mar 30. doi: 10.1038/nsmb.2995. PMID:25822993 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also User:Eric Martz/JSmol Notes