The calcium release activated calcium channel is activated by the endoplasmic reticulum-resident calcium sensor protein STIM1. On activation, STIM1 C terminus changes from an inactive, tight to an active, extended conformation. A coiled-coil clamp involving the CC1 and CC3 domains is essential in controlling STIM1 activation, with CC1 as the key entity. The nuclear magnetic resonance-derived solution structure of the CC1 domain represents a three-helix bundle stabilized by interhelical contacts, which are absent in the Stormorken disease-related STIM1 R304W mutant. Two interhelical sites between the CC1α1 and CC1α2 helices are key in controlling STIM1 activation, affecting the balance between tight and extended conformations. Nuclear magnetic resonance-directed mutations within these interhelical interactions restore the physiological, store-dependent activation behavior of the gain-of-function STIM1 R304W mutant. This study reveals the functional impact of interhelical interactions within the CC1 domain for modifying the CC1-CC3 clamp strength to control the activation of STIM1.

• MeSH
• abnormální erytrocyty MeSH
• dyslexie genetika   MeSH
• HEK293 buňky MeSH
• ichtyóza genetika   MeSH
• kanály aktivované uvolněním vápníku metabolismus   MeSH
• klonování DNA MeSH
• konformace nukleové kyseliny MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• metoda terčíkového zámku MeSH
• migréna genetika   MeSH
• mióza genetika   MeSH
• molekulární modely MeSH
• mutace genetika   MeSH
• nádorové proteiny genetika   MeSH
• protein ORAI1 genetika   MeSH
• protein STIM1 genetika   MeSH
• slezina abnormality   MeSH
• svalová únava genetika   MeSH
• trombocytopatie genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kanály aktivované uvolněním vápníku MeSH
• nádorové proteiny MeSH
• ORAI1 protein, human MeSH Prohlížeč
• protein ORAI1 MeSH
• protein STIM1 MeSH
• STIM1 protein, human MeSH Prohlížeč

The extrinsic proteins of photosystem II of higher plants and green algae PsbO, PsbP, PsbQ, and PsbR are essential for stable oxygen production in the oxygen evolving center. In the available X-ray crystallographic structure of higher plant PsbQ residues S14-Y33 are missing. Building on the backbone NMR assignment of PsbQ, which includes this "missing link", we report the extended resonance assignment including side chain atoms. Based on nuclear Overhauser effect spectra a high resolution solution structure of PsbQ with a backbone RMSD of 0.81 Å was obtained from torsion angle dynamics. Within the N-terminal residues 1-45 the solution structure deviates significantly from the X-ray crystallographic one, while the four-helix bundle core found previously is confirmed. A short α-helix is observed in the solution structure at the location where a β-strand had been proposed in the earlier crystallographic study. NMR relaxation data and unrestrained molecular dynamics simulations corroborate that the N-terminal region behaves as a flexible tail with a persistent short local helical secondary structure, while no indications of forming a β-strand are found.

• Klíčová slova
• Spinacia oleracea, dynamic N-terminus, extrinsic photosynthetic protein, hydrogen bond dynamics, intrinsic disorder, solution structure,
• MeSH
• fotosystém II (proteinový komplex) chemie   genetika   metabolismus   MeSH
• krystalografie rentgenová MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• rekombinantní proteiny chemie   metabolismus   MeSH
• rostlinné proteiny chemie   genetika   metabolismus   MeSH
• roztoky MeSH
• sekundární struktura proteinů * MeSH
• sekvence aminokyselin MeSH
• simulace molekulární dynamiky * MeSH
• Spinacia oleracea genetika   metabolismus   MeSH
• terciární struktura proteinů MeSH
• termodynamika MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fotosystém II (proteinový komplex) MeSH
• rekombinantní proteiny MeSH
• rostlinné proteiny MeSH
• roztoky MeSH

Protein structures are valuable tools to understand protein function. Nonetheless, proteins are often considered as rigid macromolecules while their structures exhibit specific flexibility, which is essential to complete their functions. Analyses of protein structures and dynamics are often performed with a simplified three-state description, i.e., the classical secondary structures. More precise and complete description of protein backbone conformation can be obtained using libraries of small protein fragments that are able to approximate every part of protein structures. These libraries, called structural alphabets (SAs), have been widely used in structure analysis field, from definition of ligand binding sites to superimposition of protein structures. SAs are also well suited to analyze the dynamics of protein structures. Here, we review innovative approaches that investigate protein flexibility based on SAs description. Coupled to various sources of experimental data (e.g., B-factor) and computational methodology (e.g., Molecular Dynamic simulation), SAs turn out to be powerful tools to analyze protein dynamics, e.g., to examine allosteric mechanisms in large set of structures in complexes, to identify order/disorder transition. SAs were also shown to be quite efficient to predict protein flexibility from amino-acid sequence. Finally, in this review, we exemplify the interest of SAs for studying flexibility with different cases of proteins implicated in pathologies and diseases.

• Klíčová slova
• allostery, disorder, protein complexes, protein folding, protein structures, protein—DNA interactions, secondary structure, structural alphabet,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH