PDBsum entry 3kld

Cell adhesion

PDB id: 3kld

Contents

Protein chains

376 a.a.

262 a.a.

Ligands

NAG ×4

Waters ×415

References listed in PDB file

Key reference

Title

The protein tyrosine phosphatases ptprz and ptprg bind to distinct members of the contactin family of neural recognition molecules.

Authors

S.Bouyain, D.J.Watkins.

Ref.

Proc Natl Acad Sci U S A, 2010, 107, 2443-2448. [DOI no: 10.1073/pnas.0911235107]

PubMed id

20133774

Abstract

The receptor protein tyrosine phosphatases gamma (PTPRG) and zeta (PTPRZ) are expressed primarily in the nervous system and mediate cell adhesion and signaling events during development. We report here the crystal structures of the carbonic anhydrase-like domains of PTPRZ and PTPRG and show that these domains interact directly with the second and third immunoglobulin repeats of the members of the contactin (CNTN) family of neural recognition molecules. Interestingly, these receptors exhibit distinct specificities: PTPRZ binds only to CNTN1, whereas PTPRG interacts with CNTN3, 4, 5, and 6. Furthermore, we present crystal structures of the four N-terminal immunoglobulin repeats of mouse CNTN4 both alone and in complex with the carbonic anhydrase-like domain of mouse PTPRG. In these structures, the N-terminal region of CNTN4 adopts a horseshoe-like conformation found also in CNTN2 and most likely in all CNTNs. This restrained conformation of the second and third immunoglobulin domains creates a binding site that is conserved among CNTN3, 4, 5, and 6. This site contacts a discrete region of PTPRG composed primarily of an extended beta-hairpin loop found in both PTPRG and PTPRZ. Overall, these findings implicate PTPRG, PTPRZ and CNTNs as a group of receptors and ligands involved in the manifold recognition events that underlie the construction of neural networks.

Figure 4.
Structure of mouse CNTN4^Ig1-4. (A) Ribbon diagram of mouse CNTN4^Ig1-4. The letters N and C indicate the N- and C-termini, respectively. Disulfide bonds are shown as orange ball-and-stick models. Asparagine-linked N-acetylglucosamine residues are depicted as gray ball-and-stick models along with the asparagine side chain. Ig domains 1, 2, 3, and 4 are colored cyan, green, gold, and red, respectively. (B) Stereo view of the interface between Ig domains 2 and 3 in CNTN4^Ig1-4. Residues at the interface between the two domains are shown as ball-and-sticks with transparent spheres (gray) and colored green (Ig2) or gold (Ig3).

Figure 6.
Stereo view of the PTPRG^CA·CNTN4^Ig1-4 interface. This view is in the same orientation as the right view in Fig. 5. Residues are shown as ball-and-sticks with transparent gray spheres for those involved in van der Waals contacts. Dashed lines indicate potential hydrogen bonds and salt bridges. Residues from CNTN4^Ig2, CNTN4^Ig3, and PTPRG^CA are colored green, gold, and magenta, respectively.