1jce
MREB FROM THERMOTOGA MARITIMA
OverviewOverview
It was thought until recently that bacteria lack the actin or tubulin filament networks that organize eukaryotic cytoplasm. However, we show here that the bacterial MreB protein assembles into filaments with a subunit repeat similar to that of F-actin-the physiological polymer of eukaryotic actin. By elucidating the MreB crystal structure we demonstrate that MreB and actin are very similar in three dimensions. Moreover, the crystals contain protofilaments, allowing visualization of actin-like strands at atomic resolution. The structure of the MreB protofilament is in remarkably good agreement with the model for F-actin, showing that the proteins assemble in identical orientations. The actin-like properties of MreB explain the finding that MreB forms large fibrous spirals under the cell membrane of rod-shaped cells, where they are involved in cell-shape determination. Thus, prokaryotes are now known to possess homologues both of tubulin, namely FtsZ, and of actin.
About this StructureAbout this Structure
1JCE is a Single protein structure of sequence from Thermotoga maritima. Full crystallographic information is available from OCA.
ReferenceReference
Prokaryotic origin of the actin cytoskeleton., van den Ent F, Amos LA, Lowe J, Nature. 2001 Sep 6;413(6851):39-44. PMID:11544518 Page seeded by OCA on Fri May 2 21:03:00 2008