Acta Crystallographica Section D

Biological Crystallography

Volume 64, Part 4 (April 2008)

research papers

Acta Cryst. (2008). D64, 377-382 [ doi:10.1107/S0907444908000474 ]

Structures of the N47A and E109Q mutant proteins of pyruvoyl-dependent arginine decarboxylase from Methanococcus jannaschii

E. V. Soriano, D. E. McCloskey, C. Kinsland, A. E. Pegg and S. E. Ealick

Abstract: Pyruvoyl-dependent arginine decarboxylase (PvlArgDC) catalyzes the first step of the polyamine-biosynthetic pathway in plants and some archaebacteria. The pyruvoyl group of PvlArgDC is generated by an internal autoserinolysis reaction at an absolutely conserved serine residue in the proenzyme, resulting in two polypeptide chains. Based on the native structure of PvlArgDC from Methanococcus jannaschii, the conserved residues Asn47 and Glu109 were proposed to be involved in the decarboxylation and autoprocessing reactions. N47A and E109Q mutant proteins were prepared and the three-dimensional structure of each protein was determined at 2.0 Å resolution. The N47A and E109Q mutant proteins showed reduced decarboxylation activity compared with the wild-type PvlArgDC. These residues may also be important for the autoprocessing reaction, which utilizes a mechanism similar to that of the decarboxylation reaction.

PDB references: 2qqc and 2qqd

Keywords: arginine decarboxylase; pyruvoyl; decarboxylation; autoprocessing; serinolysis.