Download MendeleyCryo-EM structure of the bacterial actin AlfA reveals unique assembly and ATP-binding interactions and the absence of a conserved subdomain.
Usluer, G.D., DiMaio, F., Yang, S.K., Hansen, J.M., Polka, J.K., Mullins, R.D., Kollman, J.M.(2018) Proc Natl Acad Sci U S A 115: 3356-3361
- PubMed: 29440491
- DOI: https://doi.org/10.1073/pnas.1715836115
- Primary Citation of Related Structures:
6BQW - PubMed Abstract:
Bacterial actins are an evolutionarily diverse family of ATP-dependent filaments built from protomers with a conserved structural fold. Actin-based segregation systems are encoded on many bacterial plasmids and function to partition plasmids into daughter cells. The bacterial actin AlfA segregates plasmids by a mechanism distinct from other partition systems, dependent on its unique dynamic properties. Here, we report the near-atomic resolution electron cryo-microscopy structure of the AlfA filament, which reveals a strikingly divergent filament architecture resulting from the loss of a subdomain conserved in all other actins and a mode of ATP binding. Its unusual assembly interfaces and nucleotide interactions provide insight into AlfA dynamics, and expand the range of evolutionary variation accessible to actin quaternary structure.
Organizational Affiliation:
Department of Biochemistry, University of Washington, Seattle, WA 98195.
