TY  - JOUR
A1  - Stehle, Tanja
A1  - Sreeramulu, Sridhar
A1  - Löhr, Frank
A1  - Richter, Christian
A1  - Saxena, Krishna
A1  - Jonker, Hendrik R. A.
A1  - Schwalbe, Harald
T1  - The apo-structure of the low molecular weight protein-tyrosine phosphatase A (MptpA) from Mycobacterium tuberculosis allows for better target-specific drug development
T2  - Journal of biological chemistry
N2  - Protein-tyrosine phosphatases (PTPs) and protein-tyrosine kinases co-regulate cellular processes. In pathogenic bacteria, they are frequently exploited to act as key virulence factors for human diseases. Mycobacterium tuberculosis, the causative organism of tuberculosis, secretes a low molecular weight PTP (LMW-PTP), MptpA, which is required for its survival upon infection of host macrophages. Although there is otherwise no sequence similarity of LMW-PTPs to other classes of PTPs, the phosphate binding loop (P-loop) CX5R and the loop containing a critical aspartic acid residue (D-loop), required for the catalytic activity, are well conserved. In most high molecular weight PTPs, ligand binding to the P-loop triggers a large conformational reorientation of the D-loop, in which it moves ∼10 Å, from an “open” to a “closed” conformation. Until now, there have been no ligand-free structures of LMW-PTPs described, and hence the dynamics of the D-loop have remained largely unknown for these PTPs. Here, we present a high resolution solution NMR structure of the free form of the MptpA LMW-PTP. In the absence of ligand and phosphate ions, the D-loop adopts an open conformation. Furthermore, we characterized the binding site of phosphate, a competitive inhibitor of LMW-PTPs, on MptpA and elucidated the involvement of both the P- and D-loop in phosphate binding. Notably, in LMW-PTPs, the phosphorylation status of two well conserved tyrosine residues, typically located in the D-loop, regulates the enzyme activity. PtkA, the kinase complementary to MptpA, phosphorylates these two tyrosine residues in MptpA. We characterized the MptpA-PtkA interaction by NMR spectroscopy to show that both the P- and D-loop form part of the binding interface.
KW  - Bacterial Protein Kinases
KW  - Bacterial Protein Phosphatases
KW  - Drug Resistance
KW  - Mycobacterium tuberculosis
KW  - NMR
KW  - MptpA
KW  - PtkA
KW  - Low Molecular Weight PTP
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/76675
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-766758
SN  - 0021-9258
VL  - 287.2012
IS  - 41
SP  - 34569
EP  - 34582
PB  - American Society for Biochemistry and Molecular Biology Publications
CY  - Bethesda, Md
ER  -