4BQL

Crystal structure of archaeal actin

Summary for 4BQL

• Entry DOI: 10.2210/pdb4bql/pdb
• Descriptor: ACTIN/ACTIN FAMILY PROTEIN, ADENOSINE-5'-DIPHOSPHATE, MAGNESIUM ION (3 entities in total)
• Functional Keywords: contractile protein, archaea, crenarchaeota, cytoskeleton, evolution
• Biological source: PYROBACULUM CALIDIFONTIS
• Total number of polymer chains: 4
• Total formula weight: 205138.24

Authors

Lindaas, A.-C.,Chruszsz, M.,Bernander, R.,Valegard, K. (deposition date: 2013-05-31, release date: 2014-02-12, Last modification date: 2024-05-08)

Primary citation

Lindas, A.C.,Chruszcz, M.,Bernander, R.,Valegard, K.
Structure of Crenactin, an Archaeal Actin Homologue Active at 90Degc.
Acta Crystallogr.,Sect.D, 70:492-, 2014

PubMed Abstract: The crystal structure of the archaeal actin, crenactin, from the rod-shaped hyperthermophilic (optimal growth at 90°C) crenarchaeon Pyrobaculum calidifontis is reported at 3.35 Å resolution. Despite low amino-acid sequence identity, the three-dimensional structure of the protein monomer is highly similar to those of eukaryotic actin and the bacterial MreB protein. Crenactin-specific features are also evident, as well as elements that are shared between crenactin and eukaryotic actin but are not found in MreB. In the crystal, crenactin monomers form right-handed helices, demonstrating that the protein is capable of forming filament-like structures. Monomer interactions in the helix, as well as interactions between crenactin and ADP in the nucleotide-binding pocket, are resolved at the atomic level and compared with those of actin and MreB. The results provide insights into the structural and functional properties of a heat-stable archaeal actin and contribute to the understanding of the evolution of actin-family proteins in the three domains of life.

PubMed: 24531483
DOI: 10.1107/S1399004714000935

Experimental method

X-RAY DIFFRACTION (3.34 Å)