Why is binding of a divalent metal cation to a structural motif containing four carboxylate residues not accompanied by a conformational change?

ABSTRACT: We earlier showed that Torpedo californica acetylcholinesterase (AChE) contains a cluster of four conserved aspartates that can strongly bind divalent cations, which we named the 4D motif. Binding of the divalent metal cations greatly increases its thermal stability. Here we systematically examined all available crystallographic structures of T. californica AChE. Two additional metal-binding sites were identified, both composed of acidic and histidine residues. Relative binding to the 4D and additional sites was studied using metadynamics simulations. It was observed that in crystal structures devoid of metal ions in the 4D site, the conformation of T. californica AChE is almost identical to that in structures in which it is occupied by a divalent metal ion. Closer examination of the 4D mo

SUBMITTER: Lushchekina S 

PROVIDER: S-EPMC11567836 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature