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-Structure paper
タイトル | Structures of actin-like ParM filaments show architecture of plasmid-segregating spindles. |
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ジャーナル・号・ページ | Nature, Vol. 523, Issue 7558, Page 106-110, Year 2015 |
掲載日 | 2015年7月2日 |
著者 | Tanmay A M Bharat / Garib N Murshudov / Carsten Sachse / Jan Löwe / |
PubMed 要旨 | Active segregation of Escherichia coli low-copy-number plasmid R1 involves formation of a bipolar spindle made of left-handed double-helical actin-like ParM filaments. ParR links the filaments with ...Active segregation of Escherichia coli low-copy-number plasmid R1 involves formation of a bipolar spindle made of left-handed double-helical actin-like ParM filaments. ParR links the filaments with centromeric parC plasmid DNA, while facilitating the addition of subunits to ParM filaments. Growing ParMRC spindles push sister plasmids to the cell poles. Here, using modern electron cryomicroscopy methods, we investigate the structures and arrangements of ParM filaments in vitro and in cells, revealing at near-atomic resolution how subunits and filaments come together to produce the simplest known mitotic machinery. To understand the mechanism of dynamic instability, we determine structures of ParM filaments in different nucleotide states. The structure of filaments bound to the ATP analogue AMPPNP is determined at 4.3 Å resolution and refined. The ParM filament structure shows strong longitudinal interfaces and weaker lateral interactions. Also using electron cryomicroscopy, we reconstruct ParM doublets forming antiparallel spindles. Finally, with whole-cell electron cryotomography, we show that doublets are abundant in bacterial cells containing low-copy-number plasmids with the ParMRC locus, leading to an asynchronous model of R1 plasmid segregation. |
リンク | Nature / PubMed:25915019 / PubMed Central |
手法 | EM (らせん対称) / EM (トモグラフィー) |
解像度 | 4.3 - 11.0 Å |
構造データ | EMDB-2848: actin-like ParM protein bound to ADP EMDB-2849: |
化合物 | ChemComp-ANP: |
由来 |
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キーワード | STRUCTURAL PROTEIN / BACTERIAL CYTOSKELETON / PLASMID SEGREGATION / ACTIN- LIKE PROTEIN / MOTOR PROTEIN / PARM / ACTIN-LIKE PROTEIN / DOUBLET / ANTIPARALLEL |