1NQA: Glyceraldehyde-3-Phosphate Dehydrogenase Mutant With Cys 149 Replaced By Ala Complexed With Nad+ And D- Glyceraldehyde-3-Phosphate

The crystal structure of the phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Bacillus stearothermophilus was solved in complex with its cofactor, NAD, and its physiological substrate, D-glyceraldehyde 3-phosphate (D-G3P). To isolate a stable ternary complex, the nucleophilic residue of the active site, Cys(149), was substituted with alanine or serine. The C149A and C149S GAPDH ternary complexes were obtained by soaking the crystals of the corresponding binary complexes (enzyme.NAD) in a solution containing G3P. The structures of the two binary and the two ternary complexes are presented. The D-G3P adopts the same conformation in the two ternary complexes. It is bound in a non-covalent way, in the free aldehyde form, its C-3 phosphate group being positioned in the P(s) site and not in the P(i) site. Its C-1 carbonyl oxygen points toward the essential His(176), which supports the role proposed for this residue along the two steps of the catalytic pathway. Arguments are provided that the structures reported here are representative of a productive enzyme.NAD.D-G3P complex in the ground state (Michaelis complex).
PDB ID: 1NQADownload
MMDB ID: 22713
PDB Deposition Date: 2003/1/21
Updated in MMDB: 2012/10
Experimental Method:
x-ray diffraction
Resolution: 2.2  Å
Source Organism:
Similar Structures:
Biological Unit for 1NQA: tetrameric; determined by author and by software (PISA)
Molecular Components in 1NQA
Label Count Molecule
Proteins (4 molecules)
Glyceraldehyde 3-phosphate Dehydrogenase
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB