2QM7

MeaB, A Bacterial Homolog of MMAA, Bound to GDP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Crystal structure and mutagenesis of the metallochaperone MeaB: insight into the causes of methylmalonic aciduria.

Hubbard, P.A.Padovani, D.Labunska, T.Mahlstedt, S.A.Banerjee, R.Drennan, C.L.

(2007) J Biol Chem 282: 31308-31316

  • DOI: 10.1074/jbc.M704850200
  • Primary Citation of Related Structures:  
    2QM7, 2QM8

  • PubMed Abstract: 
  • MeaB is an auxiliary protein that plays a crucial role in the protection and assembly of the B(12)-dependent enzyme methylmalonyl-CoA mutase. Impairments in the human homologue of MeaB, MMAA, lead to methylmalonic aciduria, an inborn error of metabolism. To explore the role of this metallochaperone, its structure was solved in the nucleotide-free form, as well as in the presence of product, GDP ...

    MeaB is an auxiliary protein that plays a crucial role in the protection and assembly of the B(12)-dependent enzyme methylmalonyl-CoA mutase. Impairments in the human homologue of MeaB, MMAA, lead to methylmalonic aciduria, an inborn error of metabolism. To explore the role of this metallochaperone, its structure was solved in the nucleotide-free form, as well as in the presence of product, GDP. MeaB is a homodimer, with each subunit containing a central alpha/beta-core G domain that is typical of the GTPase family, as well as alpha-helical extensions at the N and C termini that are not found in other metalloenzyme chaperone GTPases. The C-terminal extension appears to be essential for nucleotide-independent dimerization, and the N-terminal region is implicated in protein-protein interaction with its partner protein, methylmalonyl-CoA mutase. The structure of MeaB confirms that it is a member of the G3E family of P-loop GTPases, which contains other putative metallochaperones HypB, CooC, and UreG. Interestingly, the so-called switch regions, responsible for signal transduction following GTP hydrolysis, are found at the dimer interface of MeaB instead of being positioned at the surface of the protein where its partner protein methylmalonyl-CoA mutase should bind. This observation suggests a large conformation change of MeaB must occur between the GDP- and GTP-bound forms of this protein. Because of their high sequence homology, the missense mutations in MMAA that result in methylmalonic aciduria have been mapped onto MeaB and, in conjunction with mutagenesis data, provide possible explanations for the pathology of this disease.


    Organizational Affiliation

    Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
GTPase/ATPaseA, B337Methylorubrum extorquens AM1Mutation(s): 3 
Gene Names: meaB
UniProt
Find proteins for Q8RPA0 (Methylorubrum extorquens)
Explore Q8RPA0 
Go to UniProtKB:  Q8RPA0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8RPA0
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GDP
Query on GDP

Download Ideal Coordinates CCD File 
E [auth A],
F [auth B]
GUANOSINE-5'-DIPHOSPHATE
C10 H15 N5 O11 P2
QGWNDRXFNXRZMB-UUOKFMHZSA-N
 Ligand Interaction
PO4
Query on PO4

Download Ideal Coordinates CCD File 
C [auth A],
D [auth A]
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Binding Affinity Annotations 
IDSourceBinding Affinity
GDP PDBBind:  2QM7 Kd: 1300 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.06α = 90
b = 79.15β = 110.93
c = 71.07γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
CNSrefinement
ADSCdata collection
DENZOdata reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-08-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Source and taxonomy, Version format compliance
  • Version 1.2: 2019-07-24
    Changes: Data collection, Refinement description
  • Version 1.3: 2021-10-20
    Changes: Database references, Derived calculations