Crystal structure of the non-regulatory A(4 )isoform of spinach chloroplast glyceraldehyde-3-phosphate dehydrogenase complexed with NADP.Fermani, S., Ripamonti, A., Sabatino, P., Zanotti, G., Scagliarini, S., Sparla, F., Trost, P., Pupillo, P.
(2001) J.Mol.Biol. 314: 527-542
- PubMed: 11846565
- DOI: 10.1006/jmbi.2001.5172
- PubMed Abstract:
- The non-regulatory isoform of NADP(H)-glyceraldehyde-3-phosphate dehydrogenase from spinach chloroplasts
Scagliarini, S.,Trost, P.,Pupillo, P.
(1998) J.Exp.Bot. 49: 1307
- Chloroplast glyceraldehyde-3-phosphate dehydrogenase (NADP): amino acid sequence of the subunits from isoenzyme I and structural relationship with isoenzyme II.
Ferri, G.,Stoppini, M.,Meloni, M.,Zapponi, M.C.,Iadarola, P.
(1990) Biochim.Biophys.Acta 1041: 36
- Crystallization and preliminary X-ray study of chloroplast glyceraldehyde-3-phosphate dehydrogenase
Sabatino, P.,Fermani, S.,Ripamonti, A.,Cassetta, A.,Scagliarini, S.,Trost, P.
(1999) Acta Crystallogr.,Sect.D 55: 566
Here, we report the first crystal structure of a photosynthetic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) complexed with NADP. The enzyme, purified from spinach chloroplasts, is constituted of a single type of subunit (A) arranged in homotetra ...
Here, we report the first crystal structure of a photosynthetic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) complexed with NADP. The enzyme, purified from spinach chloroplasts, is constituted of a single type of subunit (A) arranged in homotetramers. It shows non-regulated NADP-dependent and NAD-dependent activities, with a preference for NADP. The structure has been solved to 3.0 A resolution by molecular replacement. The crystals belong to space group C222 with three monomers in the asymmetric unit. One of the three monomers generates a tetramer using the space group 222 point symmetry and a very similar tetramer is generated by the other two monomers, related by a non-crystallographic symmetry, using a crystallographic 2-fold axis. The protein reveals a large structural homology with known GAPDHs both in the cofactor-binding domain and in regions of the catalytic domain. Like all other GAPDHs investigated so far, the A(4)-GAPDH belongs to the Rossmann fold family of dehydrogenases. However, unlike most dehydrogenases of this family, the adenosine 2'-phosphate group of NADP does not form a salt-bridge with any positively charged residue in its surroundings, being instead set in place by hydrogen bonds with a threonine residue belonging to the Rossmann fold and a serine residue located in the S-loop of a symmetry-related monomer. While increasing our knowledge of an important photosynthetic enzyme, these results contribute to a general understanding of NADP versus NAD recognition in pyridine nucleotide-dependent enzymes. Although the overall structure of A(4)-GAPDH is similar to that of the cytosolic GAPDH from bacteria and eukaryotes, the chloroplast tetramer is peculiar, in that it can actually be considered a dimer of dimers, since monomers are bound in pairs by a disulphide bridge formed across Cys200 residues. This bridge is not found in other cytosolic or chloroplast GAPDHs from animals, bacteria, or plants other than spinach.
Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, Bologna, 40126, Italia. firstname.lastname@example.org