Publication Date:
1990-07-20
Description:
The 70-residue carboxyl-terminal domain of the muscle contractile protein troponin-C contains two helix-loop-helix calcium (Ca)-binding sites that are related to each other by approximate twofold rotational symmetry. Hydrophobic residues from the helices and a short three residue beta sheet at the interface of the two sites act to stabilize the protein domain in the presence of Ca. A synthetic 34-residue peptide representing one of these sites (site III) has been synthesized and studied by H-1 nuclear magnetic resonance (NMR) spectroscopy. In solution this peptide undergoes a Ca-induced conformational change to form the helix-loop-helix Ca-binding motif. Two-dimensional nuclear Overhauser effect spectra have provided evidence for the formation of a beta sheet and interactions between several hydrophobic residues from opposing helices as found in troponin-C. It is proposed that a symmetric two-site dimer similar in tertiary structure to the carboxyl-terminal domain of troponin-C forms from the assembly of two site III peptides in the Ca-bound form.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shaw, G S -- Hodges, R S -- Sykes, B D -- New York, N.Y. -- Science. 1990 Jul 20;249(4966):280-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Alberta, Edmonton, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2374927" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Animals
;
Binding Sites
;
Calcium/*metabolism/pharmacology
;
Hydrogen
;
Magnetic Resonance Spectroscopy/methods
;
Models, Molecular
;
Molecular Sequence Data
;
Peptides/chemical synthesis/*metabolism
;
Protein Conformation
;
Troponin/chemical synthesis/*metabolism
;
Troponin C
;
Turkeys
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
