Heavy riboflavin synthase from Bacillus subtilis

Bacher, Adelbert; Ludwig, Heide C.; Schnepple, Harald; Ben‐Shaul, Yehuda

doi:10.1016/0022-2836(86)90407-9

Cited by 76 publications

(72 citation statements)

References 33 publications

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“…The p subunit binds one molecule of the substrate analogs (structures 5 or 6, Fig. 3) directly within the activesite region [4]. The substrate analog inhibitors mentioned above have been used in ligand-driven reaggregation leading to hollow p6,, particles that were used to obtain the hexagonal and monoclinic crystal modifications [lo, 111.…”

Section: Substrate-binding Site and Catalysismentioning

confidence: 99%

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confidence: 99%

“…The overall shape of the enzyme complex is spherical as shown by electron microscopy and small-angle X-ray scattering [2][3][4]81. These data immediately suggested that the complex should be characterized by icosahedral symmetry [2, 31.…”

mentioning

confidence: 99%

“…These data immediately suggested that the complex should be characterized by icosahedral symmetry [2, 31. On the basis of immunochemical data, it was further proposed that the three a subunits should be located in the central core of the icosahedral P-subunit capsid [4]. X-ray crystallographic studies of the 03,/?60 complex at a reqolution of 0.33 nm confirmed the icosahedral symmetry of the p-subunit capsid which can be visualized as an assembly of 12 densely packed pentons IS, 91.…”

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confidence: 99%

“…Under these conditions, the asubunit trimers are released from the complex, and the ,/?-subunits form large vesicular structures with diameters of 26.0-30.0 nm. From these aggregates, it is possible to generate empty icosahedral capsids by ligand-driven renaturation in urea [4,10,111. Electron microscopy, hydrodynamic studies and small-angle X-ray scattering showed that the reconstituted particles have similar dimensions as the native complex [4,8,121.…”

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confidence: 99%

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The lumazine synthase/riboflavin synthase complex of Bacillus subtilis

Ladenstein

Ritsert

Huber

et al. 1994

European Journal of Biochemistry

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The lumazine synthasehiboflavin synthase complex of Bacillus subtilis consists of an icosahedral capsid of 60 P subunits enclosing a triplet of a subunits. An X-ray structure of 0.32 nm resolution has been obtained for the icosahedral capsid of the native a3P6,, complex [Ladenstein, R., Schneider, M., Huber, R., Bartunik P subunits were isolated after denaturation of the a&, complex and were subsequently reconstituted in a ligand-driven reaction yielding artifactual, hollow P 6 0 capsids with icosahedral symmetry. Hexagonal crystals (space group P6,22) of the reconstituted capsids diffracted X-rays to a resolution of 0.32 nm. Crystallographic intensity data were obtained using synchrotron radiation. Freeze-etched electron-microscopic images and rotation function calculations showed that the hexagonal crystal forms of the artifactual P 6 0 capsids and the native @$60 complex are isomorphous. Orientation and translation parameters of the P-subunit model were refined by XPLOR rigid-body refinement. The electron-density map was improved by cyclic icosahedral averaging and phase extension from 0.5 -0.32 nm resolution. The P-subunit structure was partially refined by energy minimization and crystallographic refinement (XPLOR) assuming strict icosahedral symmetry (final R factor 30.9% for data at 0.8-0.32 nm resolution).The topology and chain folding of the P subunits in the artifactual Pbo capsid are similar to the native enzyme. Structural features of the substrate-binding site and the binding of the substrateanalogous ligand 5-nitro-6-ribitylamino-2,4(1H,3H)-pyrimidinedione are discussed. Ligand binding occurs at the pentamer interfaces and includes van der Waals' interactions and hydrogen bonding. The binding pocket shows a hydrophobic region which accomodates the pyrimidinedione ring and a hydrophilic region to which the ribityl side chain binds. Most amino acid residues involved in the active site are conserved as shown by sequence comparisons with the putative lumazine-synthase genes of Escherichia coli and Photobacterium leiognathi. In the final electron-density map, a residual density feature was tentatively assigned to a bound phosphate ion which mimics the binding of the second substrate, 3,4-dihydroxy-2-butanone 4-phosphate. This putative phosphate-binding site involves a highly conserved amino acid sequence containing three basic residues. 203, 1045 -10701.The biosynthesis of riboflavin in Bacillus subtilis involves an enzyme with an unusual structure which has been formerly designated as heavy riboflavin synthase [l]. Recent enzymological evidence suggests that this protein can now be addressed more accurately as a 6,7-dimethyl-8-ribityllumazine synthasehiboflavin synthase. The reactions catalyzed by the enzyme complex are shown in Fig. 1.The structure of this enzyme complex has been studied in some detail [I]. The protein consists of three a subunits and 60 / 3 subunits [2-41. The p subunits catalyze the formation of 6,7-dimethyl-8-ribityllumazine (Fig. l , structure 3 condensation of the pyrimidinedione...

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Section: Substrate-binding Site and Catalysismentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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The lumazine synthase/riboflavin synthase complex of Bacillus subtilis

Ladenstein

Ritsert

Huber

et al. 1994

European Journal of Biochemistry

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Design of Biofunctional Assemblies on Solids through Recombinant Spherical Bacterial Protein Lumazine Synthase

et al. 2001

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Synthesis of Nanophase Iron Oxide in Lumazine Synthase Capsids

et al. 2001

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Ein Bionanoreaktor auf Enzymbasis: Lumazinsynthase, ein aus 60 Untereinheiten bestehender, hohlraumförmiger Enzymkomplex, kann als Biomineralisationstemplat für die Herstellung von nanokristallinem Eisenoxid dienen. Eisenionen können die Hülle durch hydrophile, trichterförmige Kanäle durchdringen, die mit Glutaminsäureresten ausgekleidet sind (siehe Bild), und werden im Hohlraum in Form von FeIII‐Oxid eingeschlossen. Bei Erhöhung der FeIII‐Ionenkonzentration nimmt der Durchmesser der Hülle infolge der Bildung einer Struktur höherer Ordnung von 15 auf 30 nm zu.

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Heavy riboflavin synthase from Bacillus subtilis

Cited by 76 publications

References 33 publications

The lumazine synthase/riboflavin synthase complex of Bacillus subtilis

The lumazine synthase/riboflavin synthase complex of Bacillus subtilis

Design of Biofunctional Assemblies on Solids through Recombinant Spherical Bacterial Protein Lumazine Synthase

Synthesis of Nanophase Iron Oxide in Lumazine Synthase Capsids

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