PDBsum entry 2c9a

Hydrolase

PDB id: 2c9a

Contents

Protein chain

259 a.a. *

Ligands

NAG-NAG-MAN-MAN

NAG-NAG-FUC

NAG

Metals

_NA ×2

Waters ×67

* Residue conservation analysis

PDB id:

2c9a

Name:

Hydrolase

Title:

Crystal structure of the mam-ig module of receptor protein tyrosine phosphatase mu

Structure:

Receptor-type tyrosine-protein phosphatase mu. Chain: a. Fragment: mam-ig module residues 21-279. Synonym: receptor protein tyrosine phosphatase mu, r-ptp-mu. Engineered: yes

Source:

Homo sapiens. Organism_taxid: 9606. Expressed in: homo sapiens. Expression_system_taxid: 9606. Expression_system_cell_line: hek-293t.

Resolution:

2.70Å R-factor: 0.225 R-free: 0.275

Authors:

A.R.Aricescu,W.C.Hon,C.Siebold,W.Lu,P.A.Van Der Merwe,E.Y.Jones

Key ref:

A.R.Aricescu et al. (2006). Molecular analysis of receptor protein tyrosine phosphatase mu-mediated cell adhesion. EMBO J, 25, 701-712. PubMed id: 16456543 DOI: 10.1038/sj.emboj.7600974

Date:

09-Dec-05 Release date: 19-Jan-06

Protein chain

P28827  (PTPRM_HUMAN) -  Receptor-type tyrosine-protein phosphatase mu from Homo sapiens

Seq: 1452 a.a.

Struc: 259 a.a.

Enzyme reactions

• Enzyme class: E.C.3.1.3.48 - protein-tyrosine-phosphatase.
• Reaction: O-phospho-L-tyrosyl-[protein] + H2O = L-tyrosyl-[protein] + phosphate

O-phospho-L-tyrosyl-[protein] + H2O = L-tyrosyl-[protein] (Bound ligand (Het Group name = NAG) matches with 47.62% similarity) + phosphate

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Key reference

DOI no: 10.1038/sj.emboj.7600974

EMBO J 25:701-712 (2006)

PubMed id: 16456543

Molecular analysis of receptor protein tyrosine phosphatase mu-mediated cell adhesion.

A.R.Aricescu, W.C.Hon, C.Siebold, W.Lu, P.A.van der Merwe, E.Y.Jones.

ABSTRACT

Type IIB receptor protein tyrosine phosphatases (RPTPs) are bi-functional cell surface molecules. Their ectodomains mediate stable, homophilic, cell-adhesive interactions, whereas the intracellular catalytic regions can modulate the phosphorylation state of cadherin/catenin complexes. We describe a systematic investigation of the cell-adhesive properties of the extracellular region of RPTPmu, a prototypical type IIB RPTP. The crystal structure of a construct comprising its N-terminal MAM (meprin/A5/mu) and Ig domains was determined at 2.7 A resolution; this assigns the MAM fold to the jelly-roll family and reveals extensive interactions between the two domains, which form a rigid structural unit. Structure-based site-directed mutagenesis, serial domain deletions and cell-adhesion assays allowed us to identify the four N-terminal domains (MAM, Ig, fibronectin type III (FNIII)-1 and FNIII-2) as a minimal functional unit. Biophysical characterization revealed at least two independent types of homophilic interaction which, taken together, suggest that there is the potential for formation of a complex and possibly ordered array of receptor molecules at cell contact sites.

Selected figure(s)

Figure 1.
Figure 1 The MIg crystal structure and analysis of the MAM domain. (A) Ribbon diagram of MIg. The MAM-Ig linker in the MAM domain is highlighted in purple. Disulphide bonds (orange) and the N-glycosylation sites (CPK) are presented as stick models. The N- and C-termini are labelled. Inset shows the L-shape of the molecule. Arrowhead indicates the largest crystal contact site. (B) Comparisons of the MAM domain to two closely related -sandwich structures. Ribbon diagrams are shown for comparisons of secondary structures and molecular surfaces are shown to display surface features of binding sites (marked by arrowheads). Structurally equivalent regions (inter-C distances <3.0 Å) are shown in green and structurally distinct regions are highlighted (blue in front of the -sandwich and red at the back). In 1GUI:A, the blue loops demarcate the carbohydrate-binding groove. In 1KGY:A, the red loops surround the hydrophobic ephrinB2-binding pocket, which constitutes the primary dimerization site; the blue loop forms the second ephrinB2-binding site. Regions that are not superposable are coloured in grey. Disulphide bonds are shown as orange sticks. All three structures are shown from the same view upon superimposition on MAM. (C) Structural details of the MAM L1 and L2 loops. The L1 and L2 loops are depicted in stick representation whereas the remainder of the MAM domain is shown as a solid surface. Residues selected for mutagenesis studies are highlighted with yellow carbon atoms. Phe68 (shown in pink) corresponds to the F74S cancer-linked mutation in RPTP . As in panel A, linker residues are coloured in purple and cysteines in orange. Asparagine residues providing sites for N-linked glycosylation are distinguished by standard atom colouring (carbon: white, nitrogen: blue, oxygen: red). This figure was produced using Pymol (http://pymol.sourceforge.net/).

Figure 3.
Figure 3 Cell-adhesion assays. Insect Sf9 cells expressing transmembrane RPTP EGFP-fusion constructs were observed by fluorescence microscopy. All RPTP fusion constructs (except for Ex -TM-EGFP) have JM-D1-EGFP in the intracellular region, and are expressed at the plasma membrane (indicated by white arrows); whereas EGFP alone (control) is expressed uniformly in the cytosol. The bright intracellular signal indicates overexpression of the constructs in the endoplasmic reticulum and the Golgi apparatus. Note the localization of MIF2, MIF3, Ex and its mutants (L1m, L2m) at the cell–cell contact regions (also see Figure 5B and C). IF14t and F14t fusion constructs (not shown) did not induce cell aggregation. The Ex -TM-EGFP construct contains only the first 10 intracellular residues of RPTP . Scale bar: 250 m for the epifluorescence images; 20 m (for constructs that form cell aggregates) and 10 m (others) for the confocal images.

The above figures are reprinted from an Open Access publication published by Macmillan Publishers Ltd: EMBO J (2006, 25, 701-712) copyright 2006.

Figures were selected by an automated process.