Structural complexity of filaments formed from the actin and tubulin folds

Figures & data

Figure 1. Two views of the structures of filaments formed from the actin (blue/orange) and tubulin (red/yellow) folds. The actins are: the twisted single-stranded crenactin from the archaeon Pyrobaculum calidifontis,^33,39 Caulobacter crescentus MreB filament formed from an antiparallel non-twisted pair of strands (CcMreB),²³ right-handed eukaryotic F-actin,¹⁰ left-handed Escherichia coli ParM from the R1 plasmid (EcParM),³⁵ Clostridium tetani open nanotubules from the pE88 plasmid (CtParM) which are 2 antiparallel related copies of a parallel pair of strands³¹ and Bacillus thuringiensis supercoiled antiparallel filaments and nanotubules from the pBMB67 plasmid (BtParM).³⁴ The tubulins are: the eukaryotic microtubule,⁴⁰ Bacillus thuringiensis TubZ from the pBtoxis plasmid (BtTubZ)⁴¹ and Methanococcus jannaschii FtsZ (MjFtsZ).⁴² In addition the tubulin fold of BtubA/B from Prosthecobacter vanneervenii can form tubules comprised of 5 strands.⁴³

Figure 2. In the presence of molecular crowding BtParM formed rafts of filaments lying in parallel as observed by electron microscopy (A). The filaments within the rafts were not paired into a cylinder, but were supercoiled single BtParM filaments. (B) A projection image calculated from the supercoiled BtParM filament model for comparison. (C) A projection image calculated from the nanotubule model for comparison. Pairing of filaments only occurs in the presence of ParR or the ParR/parC complex.

van den Ent F, Izore T, Bharat TA, Johnson CM, Lowe J. Bacterial actin MreB forms antiparallel double filaments. Elife 2014; 3:e02634; PMID:24843005

 PubMedGoogle Scholar

Holmes KC, Popp D, Gebhard W, Kabsch W. Atomic model of the actin filament. Nature 1990; 347:44-9; PMID:2395461; http://dx.doi.org/10.1038/347044a0

 PubMed Web of Science ®Google Scholar

Gayathri P, Fujii T, Møller-Jensen J, van den Ent F, Namba K, Löwe J. A bipolar spindle of antiparallel ParM filaments drives bacterial plasmid segregation. Science 2012; 338:1334-7; PMID:23112295; http://dx.doi.org/10.1126/science.1229091

 PubMed Web of Science ®Google Scholar

Popp D, Narita A, Lee LJ, Ghoshdastider U, Xue B, Srinivasan R, Balasubramanian MK, Tanaka T, Robinson RC. Novel actin-like filament structure from Clostridium tetani. J Biol Chem 2012; 287:21121-9; PMID:22514279; http://dx.doi.org/10.1074/jbc.M112.341016

 PubMed Web of Science ®Google Scholar

Jiang S, Narita A, Popp D, Ghoshdastider U, Lee LJ, Srinivasan R, Balasubramanian MK, Oda T, Koh F, Larsson M, et al. Novel actin filaments from Bacillus thuringiensis form nanotubules for plasmid DNA segregation. Proc Natl Acad Sci U S A 2016; 113:E1200-1205; PMID:26873105; http://dx.doi.org/10.1073/pnas.1600129113

 PubMedGoogle Scholar

Sui H, Downing KH. Structural basis of interprotofilament interaction and lateral deformation of microtubules. Structure 2010; 18:1022-31; PMID:20696402; http://dx.doi.org/10.1016/j.str.2010.05.010

 PubMed Web of Science ®Google Scholar

Aylett CH, Wang Q, Michie KA, Amos LA, Lowe J. Filament structure of bacterial tubulin homologue TubZ. Proc Natl Acad Sci U S A 2010; 107:19766-71; PMID:20974911; http://dx.doi.org/10.1073/pnas.1010176107

 PubMed Web of Science ®Google Scholar

Oliva MA, Cordell SC, Lowe J. Structural insights into FtsZ protofilament formation. Nat Struct Mol Biol 2004; 11:1243-50; PMID:15558053; http://dx.doi.org/10.1038/nsmb855

 PubMed Web of Science ®Google Scholar

Pilhofer M, Ladinsky MS, McDowall AW, Petroni G, Jensen GJ. Microtubules in bacteria: Ancient tubulins build a five-protofilament homolog of the eukaryotic cytoskeleton. PLoS Biol 2011; 9:e1001213; PMID:22162949; http://dx.doi.org/10.1371/journal.pbio.1001213

 PubMed Web of Science ®Google Scholar