6J1O

Crystal structure of a SAM-dependent methyltransferase LepI from Aspergillus flavus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.182 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

Deciphering the regulatory and catalytic mechanisms of an unusual SAM-dependent enzyme.

Sun, Q.Hu, Y.Gu, Y.Huang, J.He, J.Luo, L.Yang, Y.Yin, S.Dou, C.Wang, T.Fu, X.He, L.Qi, S.Zhu, X.Yang, S.Wei, X.Cheng, W.

(2019) Signal Transduct Target Ther 4: 17-17

  • DOI: 10.1038/s41392-019-0052-y
  • Primary Citation of Related Structures:  
    6J1O, 6J24, 6J46

  • PubMed Abstract: 
  • S -adenosyl-1-methionine (SAM)-dependent enzymes regulate various disease-related behaviors in all organisms. Recently, the leporin biosynthesis enzyme LepI, a SAM-dependent enzyme, was reported to catalyze pericyclic reactions in leporin biosynthesis; however, the mechanisms underlying LepI activation and catalysis remain unclear ...

    S -adenosyl-1-methionine (SAM)-dependent enzymes regulate various disease-related behaviors in all organisms. Recently, the leporin biosynthesis enzyme LepI, a SAM-dependent enzyme, was reported to catalyze pericyclic reactions in leporin biosynthesis; however, the mechanisms underlying LepI activation and catalysis remain unclear. This study aimed to investigate the molecular mechanisms of LepI. Here, we reported crystal structures of LepI bound to SAM/5'-deoxy-5'-(methylthio) adenosine (MTA), S -adenosyl-homocysteine (SAH), and SAM/substrate states. Structural and biochemical analysis revealed that MTA or SAH inhibited the enzyme activities, whereas SAM activated the enzyme. The analysis of the substrate-bound structure of LepI demonstrated that this enzymatic retro-Claisen rearrangement was primarily driven by three critical polar residues His133, Arg197, Arg295 around the active site and assisted by SAM with unclear mechanism. The present studies indicate that the unique mechanisms underlying regulatory and catalysis of the unusual SAM-dependent enzyme LepI, not only strengthening current understanding of the fundamentally biochemical catalysis, but also providing novel insights into the design of SAM-dependent enzyme-specific small molecules.


    Organizational Affiliation

    1Division of Respiratory and Critical Care Medicine, Center of Infectious Diseases, National Clinical Research Center for Geriatrics and State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, 610041 China.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
O-methyltransferase lepIA, B387Aspergillus flavus NRRL3357Mutation(s): 0 
Gene Names: lepIAFLA_066940
EC: 2.1.1
UniProt
Find proteins for B8NJH3 (Aspergillus flavus (strain ATCC 200026 / FGSC A1120 / NRRL 3357 / JCM 12722 / SRRC 167))
Explore B8NJH3 
Go to UniProtKB:  B8NJH3
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAM (Subject of Investigation/LOI)
Query on SAM

Download Ideal Coordinates CCD File 
C [auth A], E [auth B]S-ADENOSYLMETHIONINE
C15 H22 N6 O5 S
MEFKEPWMEQBLKI-FCKMPRQPSA-N
 Ligand Interaction
MTA (Subject of Investigation/LOI)
Query on MTA

Download Ideal Coordinates CCD File 
D [auth A], F [auth B]5'-DEOXY-5'-METHYLTHIOADENOSINE
C11 H15 N5 O3 S
WUUGFSXJNOTRMR-IOSLPCCCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.182 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 160.24α = 90
b = 62.08β = 113.22
c = 113.62γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-3000data reduction
HKL-3000data scaling
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment  



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2018-12-28 
  • Released Date: 2019-05-01 
  • Deposition Author(s): Qiu, S., Wei, C.

Funding OrganizationLocationGrant Number
National Natural Science Foundation of ChinaChina20172141

Revision History  (Full details and data files)

  • Version 1.0: 2019-05-01
    Type: Initial release
  • Version 1.1: 2019-11-13
    Changes: Database references