Related Experiment Video
Updated: Aug 9, 2026
14:55
Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
NMR-derived three-dimensional solution structure of protein S complexed with calcium
S Bagby1, T S Harvey, S G Eagle
1Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, Canada.
Structure (London, England : 1993)
|February 15, 1994
Summary
The three-dimensional structure of Myxococcus xanthus Protein S reveals features explaining its stability and calcium-binding properties. This analysis suggests potential mechanisms for cell-cell adhesion and multimerization.
Area of Science:
- Structural biology
- Biochemistry
- Microbiology
Background:
- Protein S from Myxococcus xanthus is a developmentally regulated Ca(2+)-binding protein.
- It forms spore surface assemblies and may mediate cell-cell adhesion.
- Protein S shares evolutionary links with vertebrate lens beta/gamma-crystallins.
Purpose of the Study:
- To determine the 3D solution structure of Ca(2+)-loaded Protein S.
- To compare its structure with vertebrate crystallins.
- To elucidate the structural basis for its stability and function.
Main Methods:
- Multi-dimensional heteronuclear NMR spectroscopy was employed.
- Sixty structures were calculated, with 30 selected based on RMSD.
- Detailed structural analysis and comparison with X-ray crystallographic data were performed.
Main Results:
- The 3D solution structure of Ca(2+)-loaded Protein S was determined.
- Internal domains, hydrophobic cores, and surface interactions were analyzed.
- Comparisons were made with beta/gamma-crystallin structures.
Conclusions:
- Structural features explain Protein S's thermostability and differential domain stability/Ca(2+) affinity.
- Two potential multimerization modes involving Ca(2+) sites and interdomain interfaces were proposed.
- Findings may inform understanding of Ca(2+)-dependent cell-cell interactions in other systems.
Related Concept Videos
01:24Protein Organization
Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together.
The primary structure of a protein is its amino acid sequence.
The primary structure of a protein is its amino acid sequence.
01:16Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...