The activated ternary complex, enzyme-CO2-Mg(II), of the dimeric ribulose-1,5-bisphosphate carboxylase/oxygenase from Rhodospirillum rubrum can be prepared in the same crystal form that was used for the crystallographic structure determination of the nat ...
The activated ternary complex, enzyme-CO2-Mg(II), of the dimeric ribulose-1,5-bisphosphate carboxylase/oxygenase from Rhodospirillum rubrum can be prepared in the same crystal form that was used for the crystallographic structure determination of the native nonactivated enzyme (Schneider, G., Bränden, C.-I., & Lorimer, G. (1986) J. Mol. Biol. 187, 141-143). The three-dimensional structure of the activated enzyme has been determined to a nominal resolution of 2.3 A by protein crystallographic methods. The activator CO2 forms a carbamate with Lys191, located at the bottom of the funnel-shaped active site. In both subunits, this labile adduct is stabilized by a Mg(II) ion, bound to the carbamate and the side chains of Asp193 and Glu194. One solvent molecule was found within the first coordination sphere of the metal ion. The metal-binding site in ribulose-1,5-bisphosphate carboxylase consists thus of at least three protein ligands, all located on loop 2 of the beta/alpha barrel. One additional metal ligand, the side chain of the conserved Asn111, was observed close to the Mg(II) ion in the B-subunit. Other structural differences at the active site between the activated and nonactivated enzyme are limited to side-chain positions. Nevertheless, it is obvious that the hydrogen-bonding pattern in the vicinity of the activator site is completely altered.
Related Citations:
Crystallographic Refinement and Structure of Ribulose-1,5-Bisphosphate Carboxylase from Rhodospirillum Rubrum at 1.7 Angstroms Resolution Schneider, G., Lindqvist, Y., Lundqvist, T. (1990) J Mol Biol 211: 989
Crystal Structure of the Complex of Ribulose-1,5-Bisphosphate Carboxylase and a Transition State Analogue, 2-Carboxy-D-Arabinitol 1,5-Bisphosphate Lundqvist, T., Schneider, G. (1989) J Biol Chem 264: 7078
Crystal Structure of the Active Site of Ribulose-Bisphosphate Carboxylase Andersson, I., Knight, S., Schneider, G., Lindqvist, Y., Lundqvist, T., Branden, C.-I., Lorimer, G.H. (1989) Nature 337: 229
Crystal Structure of the Binary Complex of Ribulose-1,5-Bisphosphate Carboxylase and its Product, 3-Phospho-D-Glycerate Lundqvist, T., Schneider, G. (1988) J Biol Chem 263: 3643
Three-Dimensional Structure of Ribulose-1,5-Bisphosphate Carboxylase(Slash)Oxygenase from Rhodospirillum Rubrum at 2.9 Angstroms Resolution Schneider, G., Lindqvist, Y., Branden, C.-I., Lorimer, G. (1986) EMBO J 5: 3409
Organizational Affiliation:
Department of Molecular Biology, Swedish University of Agricultural Sciences, Uppsala.
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