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1qlk
From Proteopedia
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'''SOLUTION STRUCTURE OF CA(2+)-LOADED RAT S100B (BETABETA) NMR, 20 STRUCTURES''' | '''SOLUTION STRUCTURE OF CA(2+)-LOADED RAT S100B (BETABETA) NMR, 20 STRUCTURES''' | ||
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[[Category: Rustandi, R R.]] | [[Category: Rustandi, R R.]] | ||
[[Category: Weber, D J.]] | [[Category: Weber, D J.]] | ||
| - | [[Category: | + | [[Category: Calcium-binding protein]] |
| - | [[Category: | + | [[Category: Ef-hand]] |
| - | [[Category: | + | [[Category: Four-helix bundle]] |
| - | [[Category: | + | [[Category: Nmr]] |
| - | [[Category: | + | [[Category: S100 protein]] |
| - | [[Category: | + | [[Category: S100b]] |
| - | [[Category: | + | [[Category: S100beta]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 06:25:06 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 03:25, 3 May 2008
SOLUTION STRUCTURE OF CA(2+)-LOADED RAT S100B (BETABETA) NMR, 20 STRUCTURES
Overview
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.
About this Structure
1QLK is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Sat May 3 06:25:06 2008
