X-ray structures of Mn, Cd and Tb metal complexes of troponin C.Rao, S.T., Satyshur, K.A., Greaser, M.L., Sundaralingam, M.
(1996) Acta Crystallogr.,Sect.D 52: 916-922
- PubMed: 15299599
- DOI: 10.1107/S0907444996006166
- Primary Citation of Related Structures:  1NCY, 1NCZ
- PubMed Abstract:
- Molecular Structure of Troponin C from Chicken Skeletal Muscle at 3-Angstrom Resolution
Sundaralingam, M.,Bergstrom, R.,Strasburg, G.,Rao, S.T.,Roychowdhury, P.,Greaser, M.,Wang, B.C.
(1985) Science 227: 945
- Structure of Chicken Skeletal Muscle Troponin-C at 1.78 Angstroms Resolution
Satyshur, K.A.,Pyzalska, D.,Rao, S.T.,Greaser, M.,Sundaralingam, M.
(1994) Acta Crystallogr.,Sect.D 50: 40
- X-Ray Diffraction Studies of Troponin-C Crystals from Rabbit and Chicken Skeletal Muscles
Strasburg, G.M.,Greaser, M.L.,Sundaralingam, M.
(1980) J.Biol.Chem. 255: 3806
- Refined Structure of Chicken Skeletal Muscle Troponin C in the Two-Calcium State at 2-A Resolution
Satyshur, K.A.,Rao, S.T.,Pyzalska, D.,Drendel, W.,Greaser, M.,Sundaralingam, M.
(1988) J.Biol.Chem. 263: 1628
- The Amino Acid Sequence of Troponin C from Chicken Skeletal Muscle
(1976) FEBS Lett. 70: 254
The crystal structures of three metal complexes of troponin C (TnC) have been determined and refined where the two occupied structural Ca(2+) sites in the C domain have been substituted by Mn(2+), Cd(2+) and Tb(3+). The X-ray intensity data were coll ...
The crystal structures of three metal complexes of troponin C (TnC) have been determined and refined where the two occupied structural Ca(2+) sites in the C domain have been substituted by Mn(2+), Cd(2+) and Tb(3+). The X-ray intensity data were collected to 2.1, 1.8 and 1.8 A resolution, respectively, on the three metal complexes, which are isomorphous with Ca-TnC. The three complexes have r.m.s. deviations of 0.27, 0.25 and 0.35 A, respectively, for all protein atoms, from Ca-TnC. Irrespective of the charge on the metal (+2 or +3), the occupied sites 3 and 4 exhibit a distorted pentagonal bipyramidal coordination, like Ca-TnC, with seven ligands, six from the 12-residue binding loop and the seventh from a water molecule. Mn(2+) at site 4 seems to display a longer distance to one of the carboxyl bidentate ligands representing an intermediate coordination simulating the six-coordinate Mg(2+). The carboxyl O atoms of the bidentate Glu12 are displaced on the side of the equatorial plane passing through the remaining three ligands with one O atom closer to the plane (Delta of 0.11 to 0.76 A) than the other (Delta of 0.93 to 1.38 A). The two axial ligands are an aspartic carboxyl O atom and a water molecule. The metal is displaced (0.18 to 0.56 A) towards the water facing the water channel.
Department of Biochemistry, College of Agricultural & Life Sciences, University of Wisconsin-Madison, 53706, USA.