Flashcards
EF hand and Calmodulin
Cards in this deck (15)
- 1what is a motif?a conserved aa sequence, local alignment corresponding to a region whose function or structure is known, or its significance can be unknown
- 2EF hand is? what is it named from?, in what? what is it characterized by?a protein motif that is associated with Ca2+ binding.
named from the Ca2+ binding site occurring between the E and F a-helices in parvalbumin
characterized by a helix-loop-helix confirmation (like a clenched right hand) - 3there are a very large number of EF-hand containing proteins and members of this superfamily are found solely in? they bind calcium with what affinity (KD)?soley in cytosol
they bind calcium with an affinity of KD = 10^-6 M - 4what is the calcium concentration in extracellular? in intracellular (unstimulated)? in intracellular (stimulated)?1. extracellular 10^-3
in intracellular (unstimulated)? 10^-7
in intracellular (stimulated)? 10^-5 or 10^-6 - 5acidic aa's in EF hand has? that can bind Ca2+carboxylate oxygen ligands that can bind calcium
- 6how many aa does EF hand have? what qualities are its EF alpha helices and how about its conserved loop region (what it contains)?29 aa
EF hand helices are amphipathic and EF hand has a conserved loop region of hydrophobic residue (isoleucine) - 7at which position and residue of EF provide a sharp bend in the loop (helix-loop-helix)? and at which position attaches the loop to the hydrophobic core of the molecule? the first a-helix has a ____ at position 1? then hydrophobic residues facing the core at position 2, 5, 6, 9-at position 15, Gly (G) permits a sharp bend in the loop
-the Ile at position 17 attaches the loop to the hydrophobic core of the molecule
-has a Glu at position 1 (and 21 for the 2nd a-helix) - 8Summary what is a EF hand? it is a ____ that contains ___ aa, whose function is to _________?a protein motif of 29 aa,
function is to bind calcium ions tightly once concentration of Ca2+ reaches 10^-6 M - 9Calmodulin - calcium modulating protien it is a 17kDa protein which highly conserved AA sequence that contains how many EF hands? what does it bind, that in turn can bind to?4 EF hands
it binds to calcium that in turn bind to activate
kinase - 10changes in intracellular Ca2+ concentration are important signals in cells, what are Ca2+ involved in? 3 things *. many Ca2+ binding proteins contain an EF hand1. secondary messenger involved in muscle concentration
2. controls release of hormones and NT
3. involved in binding of carbohydrates by lectins
4. many Ca2+ binding proteins contain an EF hand - 11structure of calmodulin is a dumb-bell shape, the N-terminal domain has 2 EF hands separated from a similar C-terminal domain by? EF hands generally occur in ____ within globular domains and there is?a central linker region - 6-turn single a-helix
EF hands generally occur in pairs, and there is cooperative calcium binding - 12calcium binding triggers a conformational change, when 2-4 calcium ions bind to calmodulin, a conformational change is triggered and what happens?exposes a hydrophobic patch in each globular domain
- 13CaM folds at a central region (which residue)? to expose a hydrophobic patch? what does hydrophobic patch allow?folds at Ser 81 to expose hydrophobic patch
-allow interactions with other proteins , target peptide sit in a hydrophobic channel - 14what are some target enzymes for CaM?phosphorylase kinase, MLCK (myosin light chain kinase), adenylate cyclases and the Ca2+ ATP-ase
*target enzymes have a mixture of basic and hydrophobic aa's which are capable of adopting an a-helix - 15Calmodulin is a sensor of ____ and _____? the calcium/calmodulin system is part of a ?sensor of increase in intracellular calcium
and calcium enhances its affinity for a number of important regulatory proteins
-part of a signal transduction pathway
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- biological sciences Biol 115 Flashcards on EF hand and Calmodulin, created by Jenny Lee7018 on 15/05/2016.
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- Jenny Lee7018 · May 2016
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- Jun 1, 2016
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