Download MendeleyF-actin-like filaments formed by plasmid segregation protein ParM
Van den Ent, F., Moller-Jensen, J., Amos, L.A., Gerdes, K., Lowe, J.(2002) EMBO J 21: 6935-6943
- PubMed: 12486014
- DOI: https://doi.org/10.1093/emboj/cdf672
- Primary Citation of Related Structures:
1MWK, 1MWM - PubMed Abstract:
It was the general belief that DNA partitioning in prokaryotes is independent of a cytoskeletal structure, which in eukaryotic cells is indispensable for DNA segregation. Recently, however, immunofluorescence microscopy revealed highly dynamic, filamentous structures along the longitudinal axis of Escherichia coli formed by ParM, a plasmid-encoded protein required for accurate segregation of low-copy-number plasmid R1. We show here that ParM polymerizes into double helical protofilaments with a longitudinal repeat similar to filamentous actin (F-actin) and MreB filaments that maintain the cell shape of non-spherical bacteria. The crystal structure of ParM with and without ADP demonstrates that it is a member of the actin family of proteins and shows a domain movement of 25 degrees upon nucleotide binding. Furthermore, the crystal structure of ParM reveals major differences in the protofilament interface compared with F-actin, despite the similar arrangement of the subunits within the filaments. Thus, there is now evidence for cytoskeletal structures, formed by actin-like filaments that are involved in plasmid partitioning in E.coli.
Organizational Affiliation:
MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.
