2fsj

From Proteopedia

---

Revision as of 08:37, 21 November 2007

proteopedia linkproteopedia link

spinqualitylabelsall models 2fsj, resolution 1.900Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of Ta0583, an archaeal actin homolog, native data

Overview

Prokaryotic homologs of the eukaryotic structural protein actin, such as, MreB and ParM, have been implicated in determination of bacterial cell, shape, and in the segregation of genomic and plasmid DNA. In contrast to, these bacterial actin homologs, little is known about the archaeal, counterparts. As a first step, we expressed a predicted actin homolog of, the thermophilic archaeon Thermoplasma acidophilum, Ta0583, and determined, its crystal structure at 2.1A resolution. Ta0583 is expressed as a soluble, protein in T.acidophilum and is an active ATPase at physiological, temperature. In vitro, Ta0583 forms sheets with spacings resembling the, crystal lattice, indicating an inherent propensity to form filamentous, structures. The fold of Ta0583 contains the core structure of actin and, clearly belongs to the actin/Hsp70 superfamily of ATPases. Ta0583 is, approximately equidistant from actin and MreB on the structural level, and, combines features from both eubacterial actin homologs, MreB and ParM. The, structure of Ta0583 co-crystallized with ADP indicates that the nucleotide, binds at the interface between the subdomains of Ta0583 in a manner, similar to that of actin. However, the conformation of the nucleotide, observed in complex with Ta0583 clearly differs from that in complex with, actin, but closely resembles the conformation of ParM-bound nucleotide. On, the basis of sequence and structural homology, we suggest that Ta0583, derives from a ParM-like actin homolog that was once encoded by a plasmid, and was transferred into a common ancestor of Thermoplasma and, Ferroplasma. Intriguingly, both genera are characterized by the lack of a, cell wall, and therefore Ta0583 could have a function in cellular, organization.

About this Structure

2FSJ is a Single protein structure of sequence from Thermoplasma acidophilum with GOL as ligand. Full crystallographic information is available from OCA.

Reference

Crystal structure of an archaeal actin homolog., Roeben A, Kofler C, Nagy I, Nickell S, Hartl FU, Bracher A, J Mol Biol. 2006 Apr 21;358(1):145-56. Epub 2006 Feb 9. PMID:16500678

Page seeded by OCA on Wed Nov 21 10:44:30 2007