 |
PDBsum entry 3o4s
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
 |
|
|
 |
 |
 |
 |
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]
|
+
|
phosphate
|
|
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
|
Molecule diagrams generated from .mol files obtained from the
KEGG ftp site
|
|
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
|
|
|
| |
|
|
| |
|
|
J Mol Biol
405:619-629
(2011)
|
|
PubMed id:
|
|
|
|
|
| |
|
Visualizing active-site dynamics in single crystals of HePTP: opening of the WPD loop involves coordinated movement of the E loop.
|
|
D.A.Critton,
L.Tautz,
R.Page.
|
|
|
|
| |
ABSTRACT
|
|
|
| |
|
Phosphotyrosine hydrolysis by protein tyrosine phosphatases (PTPs) involves
substrate binding by the PTP loop and closure over the active site by the WPD
loop. The E loop, located immediately adjacent to the PTP and WPD loops, is
conserved among human PTPs in both sequence and structure, yet the role of this
loop in substrate binding and catalysis is comparatively unexplored.
Hematopoietic PTP (HePTP) is a member of the kinase interaction motif (KIM) PTP
family. Compared to other PTPs, KIM-PTPs have E loops that are unique in both
sequence and structure. In order to understand the role of the E loop in the
transition between the closed state and the open state of HePTP, we identified a
novel crystal form of HePTP that allowed the closed-state-to-open-state
transition to be observed within a single crystal form. These structures, which
include the first structure of the HePTP open state, show that the WPD loop
adopts an 'atypically open' conformation and, importantly, that ligands can be
exchanged at the active site, which is critical for HePTP inhibitor development.
These structures also show that tetrahedral oxyanions bind at a novel secondary
site and function to coordinate the PTP, WPD, and E loops. Finally, using both
structural and kinetic data, we reveal a novel role for E-loop residue Lys182 in
enhancing HePTP catalytic activity through its interaction with Asp236 of the
WPD loop, providing the first evidence for the coordinated dynamics of the WPD
and E loops in the catalytic cycle, which, as we show, is relevant to multiple
PTP families.
|
|
|
|
|
|
|
 |
 |
|
 |
 |
 |
 |
 |
 |
 |
 |
 |
');
}
}
 |