4R32: Crystal Structure Analysis Of Pyk2 And Paxillin Ld Motifs

Proline-rich tyrosine kinase 2 (Pyk2) is a member of the focal adhesion kinase (FAK) subfamily of cytoplasmic tyrosine kinases. The C-terminal Pyk2 focal adhesion-targeting (Pyk2-FAT) domain binds to paxillin, an adhesion molecule. Paxillin has five leucine-aspartate (LD) motifs (LD1-LD5). Here, we show that the second LD motif of paxillin, LD2, interacts with Pyk2-FAT, similar to the known Pyk2-FAT/LD4 interaction. Both LD motifs can target two ligand-binding sites on Pyk2-FAT. Interestingly, they also share similar binding affinity for Pyk2-FAT with preferential association to one site relative to the other. Nevertheless, the LD2-LD4 region of paxillin (paxillin133-290) binds to Pyk2-FAT as a 1:1 complex. However, our data suggests that the Pyk2-FAT and paxillin complex is dynamic and it appears to be a mixture of two distinct conformations of paxillin which almost equally compete for Pyk2-FAT binding. These studies provide insight into the underlying selectivity of paxillin for Pyk2 and FAK which may influence the differing behavior of these two closely-related kinases in focal adhesion sites.
PDB ID: 4R32Download
MMDB ID: 123249
PDB Deposition Date: 2014/8/13
Updated in MMDB: 2014/09
Experimental Method:
x-ray diffraction
Resolution: 3.5  Å
Source Organism:
Homo sapiens
Similar Structures:
Biological Unit for 4R32: trimeric; determined by author and by software (PISA)
Molecular Components in 4R32
Label Count Molecule
Proteins (3 molecules)
Protein-tyrosine Kinase 2-beta(Gene symbol: PTK2B)
Molecule annotation
Paxillin(Gene symbol: PXN)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB