3PO8

Structural and functional analysis of phosphothreonine-dependent FHA domain interactions

Summary for 3PO8

• Entry DOI: 10.2210/pdb3po8/pdb
• Related: 3POA
• Descriptor: Putative uncharacterized protein TB39.8, PHOSPHATE ION (3 entities in total)
• Functional Keywords: fha domain, synthetic peptide, peptide binding protein
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 1
• Total formula weight: 11042.06

Authors

Pennell, S.,Smerdon, S.J. (deposition date: 2010-11-22, release date: 2011-01-26, Last modification date: 2024-03-20)

Primary citation

Pennell, S.,Westcott, S.,Ortiz-Lombardia, M.,Patel, D.,Li, J.,Nott, T.J.,Mohammed, D.,Buxton, R.S.,Yaffe, M.B.,Verma, C.,Smerdon, S.J.
Structural and functional analysis of phosphothreonine-dependent FHA domain interactions
Structure, 18:1587-1595, 2010

PubMed Abstract: FHA domains are well established as phospho-dependent binding modules mediating signal transduction in Ser/Thr kinase signaling networks in both eukaryotic and prokaryotic species. Although they are unique in binding exclusively to phosphothreonine, the basis for this discrimination over phosphoserine has remained elusive. Here, we attempt to dissect overall binding specificity at the molecular level. We first determined the optimal peptide sequence for Rv0020c FHA domain binding by oriented peptide library screening. This served as a basis for systematic mutagenic and binding analyses, allowing us to derive relative thermodynamic contributions of conserved protein and peptide residues to binding and specificity. Structures of phosphopeptide-bound and uncomplexed Rv0020c FHA domain then directed molecular dynamics simulations which show how the extraordinary discrimination in favor of phosphothreonine occurs through formation of additional hydrogen-bonding networks that are ultimately stabilized by van der Waals interactions of the phosphothreonine γ-methyl group with a conserved pocket on the FHA domain surface.

PubMed: 21134638
DOI: 10.1016/j.str.2010.09.014

Experimental method

X-RAY DIFFRACTION (1.5 Å)