2F6F

The structure of the S295F mutant of human PTP1B

Summary for 2F6F

• Entry DOI: 10.2210/pdb2f6f/pdb
• Descriptor: Tyrosine-protein phosphatase, non-receptor type 1, CHLORIDE ION, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: phosphatase, ligand binding, mutations, hydrolase
• Biological source: Homo sapiens (human)
• Cellular location: Endoplasmic reticulum membrane; Peripheral membrane protein; Cytoplasmic side: P18031
• Total number of polymer chains: 1
• Total formula weight: 35396.15

Authors

Montalibet, J.,Skorey, K.,McKay, D.,Scapin, G.,Asante-Appiah, E.,Kennedy, B.P. (deposition date: 2005-11-29, release date: 2005-12-06, Last modification date: 2023-08-23)

Primary citation

Montalibet, J.,Skorey, K.,McKay, D.,Scapin, G.,Asante-Appiah, E.,Kennedy, B.P.
Residues distant from the active site influence protein-tyrosine phosphatase 1B inhibitor binding.
J.Biol.Chem., 281:5258-5266, 2006

PubMed Abstract: Regions of protein-tyrosine phosphatase (PTP) 1B that are distant from the active site yet affect inhibitor binding were identified by a novel library screen. This screen was based on the observation that expression of v-Src in yeast leads to lethality, which can be rescued by the coexpression of PTP1B. However, this rescue is lost when yeast are grown in the presence of PTP1B inhibitors. To identify regions of PTP1B (amino acids 1-400, catalytic domain plus 80-amino acid C-terminal tail) that can affect the binding of the difluoromethyl phosphonate (DFMP) inhibitor 7-bromo-6-difluoromethylphosphonate 3-naphthalenenitrile, a library coexpressing PTP1B mutants and v-Src was generated, and the ability of yeast to grow in the presence of the inhibitor was evaluated. PTP1B inhibitor-resistant mutations were found to concentrate on helix alpha7 and its surrounding region, but not in the active site. No resistant amino acid substitutions were found to occur in the C-terminal tail, suggesting that this region has little effect on active-site inhibitor binding. An in-depth characterization of a resistant substitution localizing to region alpha7 (S295F) revealed that this change minimally affected enzyme catalytic activity, but significantly reduced the potency of a panel of structurally diverse DFMP PTP1B inhibitors. This loss of inhibitor potency was found to be due to the difluoro moiety of these inhibitors because only the difluoro inhibitors were shifted. For example, the inhibitor potency of a monofluorinated or non-fluorinated analog of one of these DFMP inhibitors was only minimally affected. Using this type of library screen, which can scan the nearly full-length PTP1B sequence (catalytic domain and C-terminal tail) for effects on inhibitor binding, we have been able to identify novel regions of PTP1B that specifically affect the binding of DFMP inhibitors.

PubMed: 16332678
DOI: 10.1074/jbc.M511546200

Experimental method

X-RAY DIFFRACTION (2 Å)