Biological Assembly 1  

 3D View: Structure | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 30-mer - A30 

Biological assembly 1 assigned by authors.

Biological Assembly 2  

 3D View: Structure | Ligand Interaction

Global Symmetry: Icosahedral - I  (3D View)
Global Stoichiometry: Homo 60-mer - A60 

Biological assembly 2 generated by PISA,PQS (software)

Macromolecule Content

• Total Structure Weight: 501.11 kDa 
• Atom Count: 36150 
• Modelled Residue Count: 4620 
• Deposited Residue Count: 4620 
• Unique protein chains: 1

1RVV

SYNTHASE/RIBOFLAVIN SYNTHASE COMPLEX OF BACILLUS SUBTILIS

• DOI: 10.2210/pdb1RVV/pdb

• Classification: RIBOFLAVIN SYNTHASE
• Organism(s): Bacillus subtilis
• Mutation(s): No 


• Deposited: 1995-10-25 Released: 1996-12-07 
• Deposition Author(s): Ritsert, K., Huber, R., Turk, D., Ladenstein, R., Schmidt-Baese, K., Bacher, A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.40 Å
• R-Value Work: 0.237 
• R-Value Observed: 0.237 

Literature

Studies on the lumazine synthase/riboflavin synthase complex of Bacillus subtilis: crystal structure analysis of reconstituted, icosahedral beta-subunit capsids with bound substrate analogue inhibitor at 2.4 A resolution.

Ritsert, K., Huber, R., Turk, D., Ladenstein, R., Schmidt-Base, K., Bacher, A.

(1995) J Mol Biol 253: 151-167

• PubMed: 7473709 
• DOI: 10.1006/jmbi.1995.0542
• Primary Citation of Related Structures:  
  1RVV


• PubMed Abstract: 
  

The lumazine synthase/riboflavin synthase of Bacillus subtilis is a bifunctional enzyme complex catalysing the formation of riboflavin from 5-amino-6-(D-ribitylamino)-2,4(1H,3H)-pyrimidinedione and L-3,4-dihydroxy-2-butanone-4-phosphate via 6,7-dimethyl-8-ribityllumazine. The complex is composed of 3 alpha (riboflavin synthase) subunits and 60 beta (lumazine synthase) subunits and has a relative mass of 1 MDa. The 60 beta subunits are arranged in an icosahedral capsid enclosing the alpha trimer in the central core. The protein was crystallised, and an X-ray structure of the icosahedral capsid was obtained at 3.3 A resolution with a crystallographic R-factor of 0.33. Hollow, icosahedral capsids consisting of 60 beta subunits can be obtained by inhibitor-driven renaturation of isolated beta subunits. They catalyse the formation of 6,7-dimethyl-8-ribityllumazine at the same rate as the native alpha 3 beta 60 complex and can be crystallised in two different hexagonal and one monoclinic form. Crystallographic intensity data of the monoclinic crystals to a resolution of 2.4 A were obtained using synchrotron radiation and an image plate detector system. The orientation of the icosahedral molecules in the monoclinic cell was deduced by real space vector search procedures from a 3.5 A Patterson map. Phases were calculated from the model of the alpha 3 beta 60 protein and were extended by cyclic averaging exploring the 30-fold redundancy of the electron density. The 2.4 A map allowed us to refine the existing atomic model of lumazine synthase. The refined model includes 154 amino acid residues, one inhibitor molecule, 58 water molecules and one phosphate ion. Applying non-crystallographic-symmetry restraints the crystallographic R-factor is 16.7% for 100,092 reflections between 10 and 2.4 A. The chain folding of the beta subunits is closely similar to the native alpha 3 beta 60 enzyme. The lumazine synthase bears resemblance to the sugar binding proteins. The significantly higher resolution compared to the alpha 3 beta 60 structure determination allows a detailed description of the substrate analogue binding site. The environment of the 5-nitro-6-(D-ribitylamino)-2,4(1H,3H)-pyrimidinedione inhibitor is particularly rigid, and the chain segments involved in forming the active site are highly conserved for lumazine synthases of different species. A residual density feature in the final map is interpreted as a bound phosphate which mimics the binding of the second substrate. We discuss the reaction mechanism on this structural basis.

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Organizational Affiliation: 

Max-Planck-Institut für Biochemie, Martinsried, Federal Republic of Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
RIBOFLAVIN SYNTHASE	AA [auth 1], BA [auth 2], CA [auth 3], DA [auth 4], A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z	154	Bacillus subtilis	Mutation(s): 0  EC: 2.5.1.78
Find proteins for P11998 (Bacillus subtilis (strain 168)) Explore P11998  Go to UniProtKB:  P11998

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
INI	BB [auth L],  BC [auth Y],  DB [auth M],  DC [auth Z],  FA [auth A],  FB [auth N],  FC [auth 1],  HA [auth B],  HB [auth O],  HC [auth 2],  JA [auth C],  JB [auth P],  JC [auth 3],  LA [auth D],  LB [auth Q],  LC [auth 4],  NA [auth E],  NB [auth R],  PA [auth F],  PB [auth S],  RA [auth G],  RB [auth T],  TA [auth H],  TB [auth U],  VA [auth I],  VB [auth V],  XA [auth J],  XB [auth W],  ZA [auth K],  ZB [auth X]	5-NITRO-6-RIBITYL-AMINO-2,4(1H,3H)-PYRIMIDINEDIONE C9 H14 N4 O8 KSKGHNZSCSCHEQ-RPDRRWSUSA-N
PO4	AB [auth L],  AC [auth Y],  CB [auth M],  CC [auth Z],  EA [auth A],  EB [auth N],  EC [auth 1],  GA [auth B],  GB [auth O],  GC [auth 2],  IA [auth C],  IB [auth P],  IC [auth 3],  KA [auth D],  KB [auth Q],  KC [auth 4],  MA [auth E],  MB [auth R],  OA [auth F],  OB [auth S],  QA [auth G],  QB [auth T],  SA [auth H],  SB [auth U],  UA [auth I],  UB [auth V],  WA [auth J],  WB [auth W],  YA [auth K],  YB [auth X]	PHOSPHATE ION O4 P NBIIXXVUZAFLBC-UHFFFAOYSA-K

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.40 Å
• R-Value Work: 0.237 
• R-Value Observed: 0.237 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 235.9	α = 90
b = 192.6	β = 134.9
c = 168.6	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1995-10-25 
• Released Date: 1996-12-07 
Deposition Author(s): Ritsert, K., Huber, R., Turk, D., Ladenstein, R., Schmidt-Baese, K., Bacher, A.

Revision History  

• Version 1.0: 1996-12-07
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance