1R21

Solution Structure of human Ki67 FHA Domain

Summary for 1R21

• Entry DOI: 10.2210/pdb1r21/pdb
• Descriptor: Antigen Ki-67 (1 entity in total)
• Functional Keywords: beta sandwich, cell cycle
• Biological source: Homo sapiens (human)
• Cellular location: Chromosome : P46013
• Total number of polymer chains: 1
• Total formula weight: 14555.52

Authors

Byeon, I.J.,Li, H.,Tsai, M.D. (deposition date: 2003-09-25, release date: 2003-12-30, Last modification date: 2024-05-22)

Primary citation

Li, H.,Byeon, I.J.,Ju, Y.,Tsai, M.D.
Structure of Human Ki67 FHA Domain and its Binding to a Phosphoprotein Fragment from hNIFK Reveal Unique Recognition Sites and New Views to the Structural Basis of FHA Domain Functions
J.Mol.Biol., 335:371-381, 2004

PubMed Abstract: Recent studies by use of short phosphopeptides showed that forkhead-associated (FHA) domains recognize pTXX(D/I/L) motifs. Solution structures and crystal structures of several different FHA domains and their complexes with short phosphopeptides have been reported by several groups. We now report the solution structure of the FHA domain of human Ki67, a large nuclear protein associated with the cell-cycle. Using fragments of its binding partner hNIFK, we show that Ki67-hNIFK binding involves ca 44 residues without a pTXX(D/I/L) motif. The pThr site of hNIFK recognized by Ki67 FHA is pThr234-Pro235, a motif also recognized by the proline isomerase Pin1. Heteronuclear single quantum coherence (HSQC) NMR was then used to map out the binding surface, and structural analyses were used to identify key binding residues of Ki67 FHA. The results represent the first structural characterization of the complex of an FHA domain with a biologically relevant target protein fragment. Detailed analyses of the results led us to propose that three major factors control the interaction of FHA with its target protein: the pT residue, +1 to +3 residues, and an extended binding surface, and that variation in the three factors is the likely cause of the great diversity in the function and specificity of FHA domains from different sources.

PubMed: 14659764
DOI: 10.1016/j.jmb.2003.10.032

Experimental method

SOLUTION NMR