1J4O

REFINED NMR STRUCTURE OF THE FHA1 DOMAIN OF YEAST RAD53

Summary for 1J4O

• Entry DOI: 10.2210/pdb1j4o/pdb
• Descriptor: PROTEIN KINASE SPK1 (1 entity in total)
• Functional Keywords: fha domain, rad53, rad9, phosphothreonine, phosphoprotein, transferase
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Cellular location: Nucleus: P22216
• Total number of polymer chains: 1
• Total formula weight: 17093.49

Authors

Yuan, C.,Yongkiettrakul, S.,Byeon, I.-J.L.,Zhou, S.,Tsai, M.-D. (deposition date: 2001-10-03, release date: 2001-12-05, Last modification date: 2023-12-27)

Primary citation

Yuan, C.,Yongkiettrakul, S.,Byeon, I.J.,Zhou, S.,Tsai, M.D.
Solution structures of two FHA1-phosphothreonine peptide complexes provide insight into the structural basis of the ligand specificity of FHA1 from yeast Rad53.
J.Mol.Biol., 314:563-575, 2001

PubMed Abstract: Rad53, a yeast checkpoint protein involved in regulating the repair of DNA damage, contains two forkhead-associated domains, FHA1 and FHA2. Previous combinatorial library screening has shown that FHA1 strongly selects peptides containing a pTXXD motif. Subsequent location of this motif within the sequence of Rad9, the target protein, coupled with spectroscopic analysis has led to identification of a tight binding sequence that is likely the binding site of FHA1: (188)SLEV(pT)EADATFVQ(200). We present solution structures of FHA1 in complex with this pT-peptide and with another Rad9-derived pT-peptide that has ca 30-fold lower affinity, (148)KKMTFQ(pT)PTDPLE(160). Both complexes showed intermolecular NOEs predominantly between three peptide residues (pT, +1, and +2 residues) and five FHA1 residues (S82, R83, S85, T106, and N107). Furthermore, the following interactions were implicated on the basis of chemical shift perturbations and structural analysis: the phosphate group of the pT residue with the side-chain amide group of N86 and the guanidino group of R70, and the carboxylate group of Asp (at the +3 position) with the guanidino group of R83. The generated structures revealed a similar binding mode adopted by these two peptides, suggesting that pT and the +3 residue Asp are the major contributors to binding affinity and specificity, while +1 and +2 residues could provide additional fine-tuning. It was also shown that FHA1 does not bind to the corresponding pS-peptides or a related pY-peptide. We suggest that differentiation between pT and pS-peptides by FHA1 can be attributed to hydrophobic interactions between the methyl group of the pT residue and the aliphatic protons of R83, S85, and T106 from FHA1.

PubMed: 11846567
DOI: 10.1006/jmbi.2001.5140

Experimental method

SOLUTION NMR