7OC5

Alpha-humulene synthase AsR6 from Sarocladium schorii

• PDB DOI: https://doi.org/10.2210/pdb7OC5/pdb

• Classification: BIOSYNTHETIC PROTEIN
• Organism(s): Sarocladium sp. 'schorii
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2021-04-26 Released: 2021-07-07 
• Deposition Author(s): Schotte, C., Lukat, P., Deuschmann, A., Blankenfeldt, W., Cox, R.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.01 Å
• R-Value Free: 0.200 
• R-Value Work: 0.163 
• R-Value Observed: 0.164 

Starting Model: experimental

Literature

Understanding and Engineering the Stereoselectivity of Humulene Synthase.

Schotte, C., Lukat, P., Deuschmann, A., Blankenfeldt, W., Cox, R.J.

(2021) Angew Chem Int Ed Engl 60: 20308-20312

• PubMed: 34180566 
• DOI: https://doi.org/10.1002/anie.202106718
• Primary Citation of Related Structures:  
  7OC4, 7OC5, 7OC6


• PubMed Abstract: 
  

  The non-canonical terpene cyclase AsR6 is responsible for the formation of 2E,6E,9E-humulene during the biosynthesis of the tropolone sesquiterpenoid (TS) xenovulene A. The structures of unliganded AsR6 and of AsR6 in complex with an in crystallo cyclized reaction product and thiolodiphosphate reveal a new farnesyl diphosphate binding motif that comprises a unique binuclear Mg ²⁺ -cluster and an essential K289 residue that is conserved in all humulene synthases involved in TS formation. Structure-based site-directed mutagenesis of AsR6 and its homologue EupR3 identify a single residue, L285/M261, that controls the production of either 2E,6E,9E- or 2Z,6E,9E-humulene. A possible mechanism for the observed stereoselectivity was investigated using different isoprenoid precursors and results demonstrate that M261 has gatekeeping control over product formation.

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Organizational Affiliation: 

Institute for Organic Chemistry and BMWZ, Leibniz Universität Hannover, Schneiderberg 38, 30167, Hannover, Germany.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 97.3 kDa 
• Atom Count: 6,402 
• Modelled Residue Count: 764 
• Deposited Residue Count: 864 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Alpha-humulene synthase AsR6	A, B	432	Sarocladium sp. 'schorii	Mutation(s): 0  Gene Names: asR6 EC: 4.2.3.104
UniProt
Find proteins for A0A2U8U2L5 (Sarocladium schorii) Explore A0A2U8U2L5  Go to UniProtKB:  A0A2U8U2L5

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN (Subject of Investigation/LOI)	C [auth A], E [auth B]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N
MG	D [auth A]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.01 Å
• R-Value Free: 0.200 
• R-Value Work: 0.163 
• R-Value Observed: 0.164 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 121.574	α = 90
b = 55.704	β = 96.58
c = 112.045	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
Aimless	data scaling
PHASER	phasing
PDB_EXTRACT	data extraction

Structure Validation

Entry History 

Deposition Data

• Released Date: 2021-07-07 
Deposition Author(s): Schotte, C., Lukat, P., Deuschmann, A., Blankenfeldt, W., Cox, R.J.

Revision History  

• Version 1.0: 2021-07-07
  Type: Initial release
  
• Version 1.1: 2021-09-15
  Changes: Database references
• Version 1.2: 2024-05-01
  Changes: Data collection, Refinement description