1QZP

NMR structure of the human dematin headpiece domain

Summary for 1QZP

• Entry DOI: 10.2210/pdb1qzp/pdb
• Related: 1QQV 1VII
• NMR Information: BMRB: 5968
• Descriptor: dematin (1 entity in total)
• Functional Keywords: dematin headpiece, villin headpiece, actin binding domain, protein binding
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm: Q08495
• Total number of polymer chains: 1
• Total formula weight: 7936.33

Authors

Frank, B.S.,Vardar, D.,Chishti, A.H.,McKnight, C.J. (deposition date: 2003-09-17, release date: 2003-12-23, Last modification date: 2024-05-22)

Primary citation

Frank, B.S.,Vardar, D.,Chishti, A.H.,McKnight, C.J.
The NMR structure of dematin headpiece reveals a dynamic loop that is conformationally altered upon phosphorylation at a distal site
J.Biol.Chem., 279:7909-7916, 2004

PubMed Abstract: Dematin (band 4.9) is found in the junctional complex of the spectrin cytoskeleton that supports the erythrocyte cell membrane. Dematin is a member of the larger class of cytoskeleton-associated proteins that contain a modular "headpiece" domain at their extreme C termini. The dematin headpiece domain provides the second F-actin-binding site required for in vitro F-actin bundling. The dematin headpiece is found in two forms in the cell, one of 68 residues (DHP) and one containing a 22-amino acid insert near its N terminus (DHP+22). In addition, dematin contains the only headpiece domain that is phosphorylated, in vivo. The 22-amino acid insert in DHP+22 appeared unstructured in NMR spectra; therefore, we have determined the three-dimensional structure of DHP by multidimensional NMR methods. Although the overall three-dimensional structure of DHP is similar to that of the villin headpiece, there are two novel characteristics revealed by this structure. First, unlike villin headpiece that contains a single buried salt bridge, DHP contains a buried charged cluster comprising residues Glu(39), Arg(66), Lys(70), and the C-terminal carboxylate of Phe(76). Second, (15)N relaxation experiments indicate that the longer "variable loop" region near the N terminus of DHP (residues 20-29) is dynamic, undergoing significantly greater motions that the rest of the structure. Furthermore, NMR chemical shift changes indicate that the conformation of the dynamic variable loop is altered by phosphorylation of serine 74, which is far in the sequence from the variable loop region. Our results suggest that phosphorylation of the dematin headpiece acts as a conformational switch within this headpiece domain.

PubMed: 14660664
DOI: 10.1074/jbc.M310524200

Experimental method

SOLUTION NMR