7OCN

Crystal structure of the bifunctional mannitol-1-phosphate dehydrogenase/phosphatase MtlD from Acinetobacter baumannii


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.238 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Unidirectional mannitol synthesis of Acinetobacter baumannii MtlD is facilitated by the helix-loop-helix-mediated dimer formation.

Tam, H.K.Konig, P.Himpich, S.Ngu, N.D.Abele, R.Muller, V.Pos, K.M.

(2022) Proc Natl Acad Sci U S A 119: e2107994119-e2107994119

  • DOI: https://doi.org/10.1073/pnas.2107994119
  • Primary Citation of Related Structures:  
    7OCN, 7OCP, 7OCQ, 7OCR, 7OCS, 7OCT, 7OCU

  • PubMed Abstract: 

    Persistence of Acinetobacter baumannii in environments with low water activity is largely attributed to the biosynthesis of compatible solutes. Mannitol is one of the key compatible solutes in A. baumannii, and it is synthesized by a bifunctional mannitol-1-phosphate dehydrogenase/phosphatase (AbMtlD). AbMtlD catalyzes the conversion of fructose-6-phosphate to mannitol in two consecutive steps. Here, we report the crystal structure of dimeric AbMtlD, constituting two protomers each with a dehydrogenase and phosphatase domain. A proper assembly of AbMtlD dimer is facilitated by an intersection comprising a unique helix–loop–helix (HLH) domain. Reduction and dephosphorylation catalysis of fructose-6-phosphate to mannitol is dependent on the transient dimerization of AbMtlD. AbMtlD presents as a monomer under lower ionic strength conditions and was found to be mainly dimeric under high-salt conditions. The AbMtlD catalytic efficiency was markedly increased by cross-linking the protomers at the intersected HLH domain via engineered disulfide bonds. Inactivation of the AbMtlD phosphatase domain results in an intracellular accumulation of mannitol-1-phosphate in A. baumannii, leading to bacterial growth impairment upon salt stress. Taken together, our findings demonstrate that salt-induced dimerization of the bifunctional AbMtlD increases catalytic dehydrogenase and phosphatase efficiency, resulting in unidirectional catalysis of mannitol production.


  • Organizational Affiliation

    Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main D-60438, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
HAD hydrolase, family IA, variant 3
A, B
727Acinetobacter baumannii ATCC 19606 = CIP 70.34 = JCM 6841Mutation(s): 0 
Gene Names: HMPREF0010_00722
UniProt
Find proteins for D0C7J2 (Acinetobacter baumannii (strain ATCC 19606 / DSM 30007 / JCM 6841 / CCUG 19606 / CIP 70.34 / NBRC 109757 / NCIMB 12457 / NCTC 12156 / 81))
Explore D0C7J2 
Go to UniProtKB:  D0C7J2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupD0C7J2
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 6 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download Ideal Coordinates CCD File 
L [auth B]4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
SO4
Query on SO4

Download Ideal Coordinates CCD File 
D [auth A],
F [auth A],
M [auth B],
N [auth B]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
BR
Query on BR

Download Ideal Coordinates CCD File 
I [auth A]BROMIDE ION
Br
CPELXLSAUQHCOX-UHFFFAOYSA-M
EDO
Query on EDO

Download Ideal Coordinates CCD File 
E [auth A],
J [auth B]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
CL
Query on CL

Download Ideal Coordinates CCD File 
H [auth A],
O [auth B],
P [auth B],
Q [auth B]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
MG
Query on MG

Download Ideal Coordinates CCD File 
C [auth A],
G [auth A],
K [auth B]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.238 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 99.496α = 90
b = 157.418β = 90
c = 219.802γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
CRANK2phasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
German Research Foundation (DFG)GermanyFOR2251

Revision History  (Full details and data files)

  • Version 1.0: 2022-04-20
    Type: Initial release
  • Version 1.1: 2024-06-19
    Changes: Data collection