| Structural highlights
Function
[S100B_RAT] Weakly binds calcium but binds zinc very tightly-distinct binding sites with different affinities exist for both ions on each monomer. Physiological concentrations of potassium ion antagonize the binding of both divalent cations, especially affecting high-affinity calcium-binding sites. Binds to and initiates the activation of STK38 by releasing autoinhibitory intramolecular interactions within the kinase. Interaction with AGER after myocardial infarction may play a role in myocyte apoptosis by activating ERK1/2 and p53/TP53 signaling. Could assist ATAD3A cytoplasmic processing, preventing aggregation and favoring mitochondrial localization.[1] [2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The three-dimensional structure of Ca2+-bound rat S100B(betabeta) has been determined using data from a series of two-dimensional (2D), three-dimensional (3D), and four-dimensional (4D) nuclear magnetic resonance (NMR) experiments. Each S100beta subunit (91 residues) contains four helixes (helix 1, E2-R20; helix 2, K29-N38; helix 3, Q50-D61; and helix 4, F70-A83) and one antiparallel beta-sheet (strand 1, K26-K28; and strand 2, E67-D69) which brings the normal and pseudo EF-hands together. As found previously for rat apo-S100B(betabeta) [Drohat, A. C., et al. (1996) Biochemistry 35, 11577-11588], helixes 1, 1', 4, and 4' associate to form an X-type four-helix bundle at the symmetric dimer interface. Additionally, Ca2+ binding does not significantly change the interhelical angle of helixes 1 and 2 in the pseudo EF-hand (apo, Omega1-2 = 132 +/- 4 degrees; and Ca2+-bound, Omega1-2 = 137 +/- 5 degrees). However, the interhelical angle of helixes 3 and 4 in the normal EF-hand (Omega3-4 = 106 +/- 4 degrees) changed significantly upon the addition of Ca2+ (DeltaOmega3-4 = 112 +/- 5 degrees) and is similar to that of the Ca2+-bound EF-hands in calbindin D9K, calmodulin, and troponin (84 degrees </= Omega </= 128 degrees). Further, the four helixes within each S100beta subunit form a splayed-type four-helix bundle (four perpendicular helixes) as observed in Ca2+-bound calbindin D9K. The large Ca2+-dependent conformational change involving helix 3 exposes a cleft, defined by residues in the hinge region, the C-terminal loop, and helix 3, which is absent in the apo structure. This surface on Ca2+-bound S100B(betabeta) is likely important for target protein binding.
Solution structure of calcium-bound rat S100B(betabeta) as determined by nuclear magnetic resonance spectroscopy,.,Drohat AC, Baldisseri DM, Rustandi RR, Weber DJ Biochemistry. 1998 Mar 3;37(9):2729-40. PMID:9485423[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Tsoporis JN, Izhar S, Leong-Poi H, Desjardins JF, Huttunen HJ, Parker TG. S100B interaction with the receptor for advanced glycation end products (RAGE): a novel receptor-mediated mechanism for myocyte apoptosis postinfarction. Circ Res. 2010 Jan 8;106(1):93-101. doi: 10.1161/CIRCRESAHA.109.195834. Epub 2009, Nov 12. PMID:19910580 doi:10.1161/CIRCRESAHA.109.195834
- ↑ Gilquin B, Cannon BR, Hubstenberger A, Moulouel B, Falk E, Merle N, Assard N, Kieffer S, Rousseau D, Wilder PT, Weber DJ, Baudier J. The calcium-dependent interaction between S100B and the mitochondrial AAA ATPase ATAD3A and the role of this complex in the cytoplasmic processing of ATAD3A. Mol Cell Biol. 2010 Jun;30(11):2724-36. doi: 10.1128/MCB.01468-09. Epub 2010 Mar , 29. PMID:20351179 doi:10.1128/MCB.01468-09
- ↑ Drohat AC, Baldisseri DM, Rustandi RR, Weber DJ. Solution structure of calcium-bound rat S100B(betabeta) as determined by nuclear magnetic resonance spectroscopy,. Biochemistry. 1998 Mar 3;37(9):2729-40. PMID:9485423 doi:10.1021/bi972635p
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