1A54

PHOSPHATE-BINDING PROTEIN MUTANT A197C LABELLED WITH A COUMARIN FLUOROPHORE AND BOUND TO DIHYDROGENPHOSPHATE ION

Summary for 1A54

• Entry DOI: 10.2210/pdb1a54/pdb
• Descriptor: Phosphate-binding protein PstS, DIHYDROGENPHOSPHATE ION, N-[2-(1-MALEIMIDYL)ETHYL]-7-DIETHYLAMINOCOUMARIN-3-CARBOXAMIDE, ... (4 entities in total)
• Functional Keywords: phosphotransferase, transport, coumarin, fluorophore
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 34970.05

Authors

Hirshberg, M.,Henrick, K.,Lloyd-Haire, L.,Vasisht, N.,Brune, M.,Corrie, J.E.T.,Webb, M.R. (deposition date: 1998-02-19, release date: 1998-10-14, Last modification date: 2024-12-25)

Primary citation

Hirshberg, M.,Henrick, K.,Haire, L.L.,Vasisht, N.,Brune, M.,Corrie, J.E.,Webb, M.R.
Crystal structure of phosphate binding protein labeled with a coumarin fluorophore, a probe for inorganic phosphate.
Biochemistry, 37:10381-10385, 1998

PubMed Abstract: Crystal structures are presented for the A197C mutant of Escherichia coli phosphate binding protein (PBP) and the same mutant labeled at Cys197 with N-[2-(1-maleimidyl)ethyl]-7-(diethylamino)coumarin-3-carboxamide (MDCC). Both proteins are complexed with inorganic phosphate. The latter molecule, MDCC-PBP, exhibits a large increase in fluorescence on binding inorganic phosphate. The resulting high-fluorescence state of the coumarin and the ability of this coumarin to monitor the conformational changes associated with inorganic phosphate binding are interpreted in terms of the specific interactions of MDCC with the protein. The structure helps to explain why this particular label gives a high-fluorescence state on binding inorganic phosphate, while several other related labels do not, and hence aids our general understanding of environmentally sensitive fluorescence probes on proteins.

PubMed: 9671506
DOI: 10.1021/bi980428z

Experimental method

X-RAY DIFFRACTION (1.6 Å)