1F4C: CRYSTAL STRUCTURE OF E. COLI THYMIDYLATE SYNTHASE COVALENTLY MODIFIED AT C146 WITH N-[TOSYL-D-PROLINYL]AMINO-ETHANETHIOL

Citation:
Abstract
We report a strategy (called "tethering") to discover low molecular weight ligands ( approximately 250 Da) that bind weakly to targeted sites on proteins through an intermediary disulfide tether. A native or engineered cysteine in a protein is allowed to react reversibly with a small library of disulfide-containing molecules ( approximately 1,200 compounds) at concentrations typically used in drug screening (10 to 200 microM). The cysteine-captured ligands, which are readily identified by MS, are among the most stable complexes, even though in the absence of the covalent tether the ligands may bind very weakly. This method was applied to generate a potent inhibitor for thymidylate synthase, an essential enzyme in pyrimidine metabolism with therapeutic applications in cancer and infectious diseases. The affinity of the untethered ligand (K(i) approximately 1 mM) was improved 3,000-fold by synthesis of a small set of analogs with the aid of crystallographic structures of the tethered complex. Such site-directed ligand discovery allows one to nucleate drug design from a spatially targeted lead fragment.
PDB ID: 1F4CDownload
MMDB ID: 13609
PDB Deposition Date: 2000/6/7
Updated in MMDB: 2000/12
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 1F4C: dimeric; determined by author and by software (PISA)
Molecular Components in 1F4C
Label Count Molecule
Proteins (2 molecules)
2
Thymidylate Synthase(Gene symbol: thyA)
Molecule annotation
Chemicals (8 molecules)
1
5
2
2
3
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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