Structure of active cystathionine B-synthase from Apis mellifera

Experimental Data Snapshot

  • Resolution: 3.20 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 

Starting Model: experimental
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Crystal structure of cystathionine beta-synthase from honeybee Apis mellifera.

Gimenez-Mascarell, P.Majtan, T.Oyenarte, I.Ereno-Orbea, J.Majtan, J.Klaudiny, J.Kraus, J.P.Martinez-Cruz, L.A.

(2018) J Struct Biol 202: 82-93

  • DOI: https://doi.org/10.1016/j.jsb.2017.12.008
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Cystathionine β-synthase (CBS), the key enzyme in the transsulfuration pathway, links methionine metabolism to the biosynthesis of cellular redox controlling molecules. CBS catalyzes the pyridoxal-5'-phosphate-dependent condensation of serine and homocysteine to form cystathionine, which is subsequently converted into cysteine. Besides maintaining cellular sulfur amino acid homeostasis, CBS also catalyzes multiple hydrogen sulfide-generating reactions using cysteine and homocysteine as substrates. In mammals, CBS is activated by S-adenosylmethionine (AdoMet), where it can adopt two different conformations (basal and activated), but exists as a unique highly active species in fruit fly Drosophila melanogaster. Here we present the crystal structure of CBS from honeybey Apis mellifera, which shows a constitutively active dimeric species and let explain why the enzyme is not allosterically regulated by AdoMet. In addition, comparison of available CBS structures unveils a substrate-induced closure of the catalytic cavity, which in humans is affected by the AdoMet-dependent regulation and likely impaired by the homocystinuria causing mutation T191M.

  • Organizational Affiliation

    Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC Biogune), Technology Park of Bizkaia, 48160 Derio, Bizkaia, Spain.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cystathionine beta-synthase
A, B
504Apis melliferaMutation(s): 0 
Gene Names: AmCBS
Find proteins for Q2V0C9 (Apis mellifera)
Explore Q2V0C9 
Go to UniProtKB:  Q2V0C9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ2V0C9
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.20 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 86.143α = 90
b = 96.099β = 90
c = 180.684γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
Aimlessdata scaling
Cootmodel building

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2018-01-03
    Type: Initial release
  • Version 1.1: 2018-03-14
    Changes: Database references
  • Version 1.2: 2019-10-09
    Changes: Data collection
  • Version 1.3: 2024-01-17
    Changes: Data collection, Database references, Derived calculations, Refinement description