6B3B

AprA Methyltransferase 1 - GNAT in complex with Mn2+ , SAM, and Malonate

  • Classification: TRANSFERASE
  • Organism(s): Moorena bouillonii
  • Expression System: Escherichia coli BL21(DE3)
  • Mutation(s): Yes 

  • Deposited: 2017-09-21 Released: 2017-11-15 
  • Deposition Author(s): Skiba, M.A., Smith, J.L.
  • Funding Organization(s): National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK), National Institutes of Health/National Cancer Institute (NIH/NCI), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.184 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

A Mononuclear Iron-Dependent Methyltransferase Catalyzes Initial Steps in Assembly of the Apratoxin A Polyketide Starter Unit.

Skiba, M.A.Sikkema, A.P.Moss, N.A.Tran, C.L.Sturgis, R.M.Gerwick, L.Gerwick, W.H.Sherman, D.H.Smith, J.L.

(2017) ACS Chem Biol 12: 3039-3048

  • DOI: https://doi.org/10.1021/acschembio.7b00746
  • Primary Citation of Related Structures:  
    6B39, 6B3A, 6B3B

  • PubMed Abstract: 

    Natural product biosynthetic pathways contain a plethora of enzymatic tools to carry out difficult biosynthetic transformations. Here, we discover an unusual mononuclear iron-dependent methyltransferase that acts in the initiation steps of apratoxin A biosynthesis (AprA MT1). Fe 3+ -replete AprA MT1 catalyzes one or two methyl transfer reactions on the substrate malonyl-ACP (acyl carrier protein), whereas Co 2+ , Fe 2+ , Mn 2+ , and Ni 2+ support only a single methyl transfer. MT1 homologues exist within the "GNAT" (GCN5-related N-acetyltransferase) loading modules of several modular biosynthetic pathways with propionyl, isobutyryl, or pivaloyl starter units. GNAT domains are thought to catalyze decarboxylation of malonyl-CoA and acetyl transfer to a carrier protein. In AprA, the GNAT domain lacks both decarboxylation and acyl transfer activity. A crystal structure of the AprA MT1-GNAT di-domain with bound Mn 2+ , malonate, and the methyl donor S-adenosylmethionine (SAM) reveals that the malonyl substrate is a bidentate metal ligand, indicating that the metal acts as a Lewis acid to promote methylation of the malonyl α-carbon. The GNAT domain is truncated relative to functional homologues. These results afford an expanded understanding of MT1-GNAT structure and activity and permit the functional annotation of homologous GNAT loading modules both with and without methyltransferases, additionally revealing their rapid evolutionary adaptation in different biosynthetic contexts.


  • Organizational Affiliation

    Life Sciences Institute, University of Michigan , Ann Arbor, Michigan 48109, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
AprA Methyltransferase 1652Moorena bouilloniiMutation(s): 2 
UniProt
Find proteins for A0A1U7N2Z8 (Moorena bouillonii PNG)
Explore A0A1U7N2Z8 
Go to UniProtKB:  A0A1U7N2Z8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1U7N2Z8
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.184 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.705α = 90
b = 88.337β = 90
c = 136.755γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK)United StatesDK042303
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesCA108874
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM008353

Revision History  (Full details and data files)

  • Version 1.0: 2017-11-15
    Type: Initial release
  • Version 1.1: 2017-12-27
    Changes: Database references
  • Version 1.2: 2019-12-04
    Changes: Author supporting evidence
  • Version 1.3: 2023-10-04
    Changes: Data collection, Database references, Derived calculations, Refinement description