Human IMPDH2 mutant - L245P, treated with GTP, ATP, IMP, and NAD+; filament assembly interface reconstruction

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Neurodevelopmental disorder mutations in the purine biosynthetic enzyme IMPDH2 disrupt its allosteric regulation.

O'Neill, A.G.Burrell, A.L.Zech, M.Elpeleg, O.Harel, T.Edvardson, S.Mor-Shaked, H.Rippert, A.L.Nomakuchi, T.Izumi, K.Kollman, J.M.

(2023) J Biol Chem 299: 105012-105012

  • DOI: https://doi.org/10.1016/j.jbc.2023.105012
  • Primary Citation of Related Structures:  
    8FOZ, 8FUZ, 8G8F, 8G9B

  • PubMed Abstract: 

    Inosine 5' monophosphate dehydrogenase (IMPDH) is a critical regulatory enzyme in purine nucleotide biosynthesis that is inhibited by the downstream product GTP. Multiple point mutations in the human isoform IMPDH2 have recently been associated with dystonia and other neurodevelopmental disorders, but the effect of the mutations on enzyme function has not been described. Here, we report the identification of two additional missense variants in IMPDH2 from affected individuals and show that all of the disease-associated mutations disrupt GTP regulation. Cryo-EM structures of one IMPDH2 mutant suggest this regulatory defect arises from a shift in the conformational equilibrium toward a more active state. This structural and functional analysis provides insight into IMPDH2-associated disease mechanisms that point to potential therapeutic approaches and raises new questions about fundamental aspects of IMPDH regulation.

  • Organizational Affiliation

    Department of Biochemistry, University of Washington, Seattle, Washington, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Inosine-5'-monophosphate dehydrogenase 2
A, B, C, D, E
A, B, C, D, E, F, G, H
519Homo sapiensMutation(s): 1 
Gene Names: IMPDH2IMPD2
UniProt & NIH Common Fund Data Resources
Find proteins for P12268 (Homo sapiens)
Explore P12268 
Go to UniProtKB:  P12268
PHAROS:  P12268
GTEx:  ENSG00000178035 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP12268
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NAD (Subject of Investigation/LOI)
Query on NAD

Download Ideal Coordinates CCD File 
J [auth A]
L [auth B]
N [auth C]
P [auth D]
R [auth E]
J [auth A],
L [auth B],
N [auth C],
P [auth D],
R [auth E],
T [auth F],
V [auth G],
X [auth H]
C21 H27 N7 O14 P2
IMP (Subject of Investigation/LOI)
Query on IMP

Download Ideal Coordinates CCD File 
I [auth A]
K [auth B]
M [auth C]
O [auth D]
Q [auth E]
I [auth A],
K [auth B],
M [auth C],
O [auth D],
Q [auth E],
S [auth F],
U [auth G],
W [auth H]
C10 H13 N4 O8 P
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM118396
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesT32GM008268

Revision History  (Full details and data files)

  • Version 1.0: 2023-04-19
    Type: Initial release
  • Version 1.1: 2023-07-19
    Changes: Database references
  • Version 1.2: 2023-08-09
    Changes: Database references