9RP2 | pdb_00009rp2

Ensemble refined structure of CotB2 F107A in complex with alendronate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 
    0.216 (Depositor), 0.232 (DCC) 
  • R-Value Work: 
    0.179 (Depositor), 0.191 (DCC) 
  • R-Value Observed: 
    0.181 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 9RP2

Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history

Re-refinement Note

This entry reflects an alternative modeling of the original data in: 7AO0

Literature

The initial dynamics of product release in terpene synthases-The case of CotB2.

Gupta, P.K.Helmer, C.P.O.Ringel, M.Loll, B.Bruck, T.Major, D.T.

(2025) Protein Sci 34: e70312-e70312

  • DOI: https://doi.org/10.1002/pro.70312
  • Primary Citation Related Structures: 
    9RP0, 9RP1, 9RP2

  • PubMed Abstract: 

    Although the enzymatic mechanisms of terpene synthases have been extensively characterized through experimental and computational studies, the atomistic details underlying the product release process have remained elusive. In this study, we present the first atomistic simulations of the initial stages of product release in a terpene synthase, using the bacterial diterpene cyclase CotB2 as a model system. CotB2 catalyzes the complex cyclization of geranylgeranyl diphosphate (GGDP) to the tricyclic diterpene cyclooctat-9-en-7-ol in a single active site through an 11-step reaction cascade. Our MD simulations focus on three model systems representing CotB2 with bound GGDP and cyclooctat-9-en-7-ol, the latter in two states-with the diphosphate fully deprotonated (P 2 O 7 4- ) and protonated diphosphate (HP 2 O 7 3- ). Analysis of the MD trajectories clearly shows that product release is initiated by the dislocation of the diphosphate group, which in turn triggers active site opening via coordinated C-terminal motions. Notably, protonation of the diphosphate moiety appears to be the key event that weakens its interactions with the active site and enables product release. These findings provide crucial mechanistic insight into the final phase of terpene biosynthesis and open new avenues for rational enzyme engineering targeting product release.


  • Organizational Affiliation
    • Department of Chemistry and Institute for Nanotechnology & Advanced Materials and Israel National Institute for Energy Storage (INIES), Bar-Ilan University, Ramat-Gan, Israel.

Macromolecule Content 

  • Total Structure Weight: 74.57 kDa 
  • Atom Count: 5,238 
  • Modeled Residue Count: 591 
  • Deposited Residue Count: 636 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Cyclooctat-9-en-7-ol synthase
A, B
318Streptomyces melanosporofaciensMutation(s): 1 
Gene Names: CotB2
EC: 4.2.3.146
UniProt
Find proteins for C9K1X5 (Streptomyces melanosporofaciens)
Explore C9K1X5 
Go to UniProtKB:  C9K1X5
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupC9K1X5
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
AHD

Query on AHD



Download:Ideal Coordinates CCD File
D [auth A],
O [auth B]
4-AMINO-1-HYDROXYBUTANE-1,1-DIYLDIPHOSPHONATE
C4 H9 N O7 P2
OGSPWJRAVKPPFI-UHFFFAOYSA-J
MPD

Query on MPD



Download:Ideal Coordinates CCD File
C [auth A],
E [auth A],
J [auth B],
P [auth B]
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
CL

Query on CL



Download:Ideal Coordinates CCD File
I [auth A],
N [auth B]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
MG

Query on MG



Download:Ideal Coordinates CCD File
F [auth A]
G [auth A]
H [auth A]
K [auth B]
L [auth B]
F [auth A],
G [auth A],
H [auth A],
K [auth B],
L [auth B],
M [auth B]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free:  0.216 (Depositor), 0.232 (DCC) 
  • R-Value Work:  0.179 (Depositor), 0.191 (DCC) 
  • R-Value Observed: 0.181 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.811α = 90
b = 98.05β = 90
c = 106.83γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
German-Israeli Foundation for Research and DevelopmentGermanyI-85-302.14-2018
German Research Foundation (DFG)GermanyRTG 2473-1

Revision History  (Full details and data files)

  • Version 1.0: 2025-09-17
    Type: Initial release
  • Version 1.1: 2026-02-25
    Changes: Database references