Andralojc, Paul John and Madgwick, Pippa J. and Tao, Yong and Keys, Alfred and Ward, Jane L. and Beale, Michael H. and Loveland, Jane E. and Jackson, Phil J. and Willis, Antony C. and Gutteridge, Steven and Parry, Martin A. J. (2012) 2-Carboxy-D-arabinitol 1-phosphate (CA1P) phosphatase : evidence for a wider role in plant Rubisco regulation. Biochemical Journal, 442 (3). pp. 733-742. ISSN 0264-6021
Full text not available from this repository.Abstract
The genes for CA1Pase (2-carboxy-D-arabinitol-1-bisphosphate phosphatase) from French bean, wheat, Arabidopsis and tobacco were identified and cloned. The deduced protein sequence included an N-terminal motif identical with the PGM (phosphoglycerate mutase) active site sequence [LIVM]-x-R-H-G-[EQ]-x-x-[WN]. The corresponding gene from wheat coded for an enzyme with the properties published for CA1Pase. The expressed protein lacked PGM activity but rapidly dephosphorylated 2,3-DPG (2,3-diphosphoglycerate) to 2-phosphoglycerate. DTT (dithiothreitol) activation and GSSG inactivation of this enzyme was pH-sensitive, the greatest difference being apparent at pH 8. The presence of the expressed protein during in vitro measurement of Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) activity prevented a progressive decline in Rubisco turnover. This was due to the removal of an inhibitory bisphosphate that was present in the RuBP (ribulose-1,5-bisphosphate) preparation, and was found to be PDBP (D-glycero-2,3-pentodiulose-1,5- bisphosphate). The substrate specificity of the expressed protein indicates a role for CA1Pase in the removal of 'misfire' products of Rubisco.