1RM0: Crystal Structure Of Myo-Inositol 1-Phosphate Synthase From Saccharomyces Cerevisiae In Complex With Nad+ And 2-Deoxy-D-Glucitol 6-(E)-Vinylhomophosphonate

1l-myo-inositol 1-phosphate (MIP) synthase catalyzes the conversion of d-glucose 6-phosphate to 1l-myo-inositol 1-phosphate, the first and rate-limiting step in the biosynthesis of all inositol-containing compounds. It involves an oxidation, enolization, intramolecular aldol cyclization, and reduction. Here we present the structure of MIP synthase in complex with NAD(+) and a high-affinity inhibitor, 2-deoxy-d-glucitol 6-(E)-vinylhomophosphonate. This structure reveals interactions between the enzyme active site residues and the inhibitor that are significantly different from that proposed for 2-deoxy-d-glucitol 6-phosphate in the previously published structure of MIP synthase-NAD(+)-2-deoxy-d-glucitol 6-phosphate. There are several other conformational changes in NAD(+) and the enzyme active site as well. Based on the new structural data, we propose a new and completely different mechanism for MIP synthase.
PDB ID: 1RM0Download
MMDB ID: 27739
PDB Deposition Date: 2003/11/26
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.05  Å
Source Organism:
Similar Structures:
Biological Unit for 1RM0: tetrameric; determined by author and by software (PISA,PQS)
Molecular Components in 1RM0
Label Count Molecule
Proteins (4 molecules)
Myo-inositol-phosphate Synthase
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB