Phosphorylation of paxillin LD4 destabilizes helix formation and inhibits binding to focal adhesion kinase.

Cell migration is a dynamic process that requires the coordinated formation and disassembly of focal adhesions (FAs). Several proteins such as paxillin, focal adhesion kinase (FAK), and G protein-coupled receptor kinase-interacting protein 1 (GIT1) are known to play a regulatory role in FA disassembly and turnover. However, the mechanisms by which this occurs remain to be elucidated.

Structural features of the focal adhesion kinase-paxillin complex give insight into the dynamics of focal adhesion assembly.

The C-terminal region of focal adhesion kinase (FAK) consists of a right-turn, elongated, four-helix bundle termed the focal adhesion targeting (FAT) domain. The structure of this domain is maintained by hydrophobic interactions, and this domain is also the proposed binding site for the focal adhesion protein paxillin. Paxillin contains five well-conserved LD motifs, which have been implicated in the binding of many focal adhesion proteins.

Paramagnetic cobalt(II) as a probe for kinetic and NMR relaxation studies of phosphate binding and the catalytic mechanism of Streptomyces dinuclear aminopeptidase.

Phosphate was proposed to be a bridging ligand in the structure 1xjo.pdb of Streptomyces dizinc aminopeptidase (sAP), which prompted further studies of phosphate binding to this enzyme. Phosphate inhibits sAP and its Co(2+)-substituted derivatives in a noncompetitive manner from pH 6.

Nature of the displaceable heme-axial residue in the EcDos protein, a heme-based sensor from Escherichia coli.

The EcDos protein belongs to a group of heme-based sensors that detect their ligands with a heme-binding PAS domain. Among these various heme-PAS proteins, EcDos is unique in having its heme iron coordinated at both axial positions to residues of the protein. To achieve its high affinities for ligands, one of the axial heme-iron residues in EcDos must be readily displaceable.