Structure of NADP-dependent glyceraldehyde-3-phosphate dehydrogenase from Synechococcus PCC7942 complexed with NADP.
The crystal structure of NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (NADP-GAPDH) from Synechococcus PCC 7942 (S. 7942) in complex with NADP was solved by molecular replacement and refined to an R factor of 19.1% and a free R factor of 24.0% at 2.5 A resolution. The overall structure of NADP-GAPDH from S. 7942 was quite similar to those of other bacterial and eukaryotic GAPDHs. The nicotinamide ring of NADP, which is involved in the redox reaction, was oriented toward the catalytic site. The 2'-phosphate O atoms of NADP exhibited hydrogen bonds to the hydroxyl groups of Ser194 belonging to the S-loop and Thr37. These residues are therefore considered to be essential in the discrimination between NADP and NAD molecules. The C-terminal region was estimated to have an extremely flexible conformation and to play an important role in the formation of the supramolecular complex phosphoribulokinase (PRK)-regulatory peptide (CP12)-GAPDH, which regulates enzyme activities.
Kitatani
Tomoya
T
Department of Applied Biochemistry, Graduate School of Agriculture and Life Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
Nakamura
Yoshihiro
Y
Wada
Kei
K
Kinoshita
Takayoshi
T
Tamoi
Masahiro
M
Shigeoka
Shigeru
S
Tada
Toshiji
T
D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification; D003460:Crystallization; D018360:Crystallography, X-Ray; D024601:Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+) / Q000737:chemistry* / Q000302:isolation & purification; D008958:Models, Molecular; D009249:NADP / Q000737:chemistry*; D011487:Protein Conformation; D046940:Synechococcus / Q000201:enzymology*
D001426:Bacterial Proteins; D009249:NADP; D024601:Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+)