Show PDB file:   
         Plain Text   HTML   (compressed file size)
QuickSearch:   
by PDB,NDB,UniProt,PROSITE Code or Search Term(s)  
(-)Asym./Biol. Unit - manually
(-)Asym./Biol. Unit
(-)Asym./Biol. Unit - sites
collapse expand < >
Image Asym./Biol. Unit - manually
Asym./Biol. Unit - manually  (Jmol Viewer)
Image Asym./Biol. Unit
Asym./Biol. Unit  (Jmol Viewer)
Image Asym./Biol. Unit - sites
Asym./Biol. Unit - sites  (Jmol Viewer)

(-) Description

Title :  STRUCTURE OF 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE FROM SCHIZOSACCHAROMYCES POMBE MUTANT W27Y WITH BOUND LIGAND 5-NITROSO-6-RIBITYLAMINO-2,4(1H,3H)-PYRIMIDINEDIONE
 
Authors :  M. Koch, C. Breithaupt, S. Gerhardt, I. Haase, S. Weber, M. Cushman, R. H A. Bacher, M. Fischer
Date :  30 Jun 05  (Deposition) - 19 Jul 05  (Release) - 16 Jan 13  (Revision)
Method :  X-RAY DIFFRACTION
Resolution :  2.70
Chains :  Asym./Biol. Unit :  A,B,C,D,E
Keywords :  6, 7-Dimethyl-8-Ribityllumazine Synthase, Schizosaccharomyces Pombe, Mutant W27Y, Lusy, 5-Nitroso-6-Ribitylamino-2, 4(1H, 3H)- Pyrimidinedione, Transferase (Keyword Search: [Gene Ontology, PubMed, Web (Google))
 
Reference :  M. Koch, C. Breithaupt, S. Gerhardt, I. Haase, S. Weber, M. Cushman, R. Huber, A. Bacher, M. Fischer
Structural Basis Of Charge Transfer Complex Formation By Riboflavin Bound To 6, 7-Dimethyl-8-Ribityllumazine Synthase
Eur. J. Biochem. V. 271 3208 2004
PubMed-ID: 15265040  |  Reference-DOI: 10.1111/J.1432-1033.2004.04253.X

(-) Compounds

Molecule 1 - 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE
    ChainsA, B, C, D, E
    EC Number2.5.1.78
    EngineeredYES
    Expression SystemESCHERICHIA COLI
    Expression System Taxid562
    GeneRIB4
    MutationYES
    Organism CommonFISSION YEAST
    Organism ScientificSCHIZOSACCHAROMYCES POMBE
    Organism Taxid4896
    SynonymDMRL SYNTHASE, LUMAZINE SYNTHASE, RIBOFLAVIN SYNTHASE BETA CHAIN

 Structural Features

(-) Chains, Units

  12345
Asymmetric/Biological Unit ABCDE

Summary Information (see also Sequences/Alignments below)

(-) Ligands, Modified Residues, Ions  (2, 10)

Asymmetric/Biological Unit (2, 10)
No.NameCountTypeFull Name
1LMZ5Ligand/Ion5-NITROSO-6-RIBITYL-AMINO-2,4(1H,3H)-PYRIMIDINEDIONE
2PO45Ligand/IonPHOSPHATE ION

(-) Sites  (10, 10)

Asymmetric Unit (10, 10)
No.NameEvidenceResiduesDescription
01AC1SOFTWAREARG A:133 , GLY B:90 , SER B:91 , THR B:92 , HOH B:501 , HOH B:510BINDING SITE FOR RESIDUE PO4 B 500
02AC2SOFTWAREARG B:133 , GLY C:90 , SER C:91 , THR C:92 , HOH C:502 , HOH C:513BINDING SITE FOR RESIDUE PO4 C 501
03AC3SOFTWAREARG C:133 , GLY D:90 , SER D:91 , THR D:92 , HOH D:504 , HOH D:507 , HOH D:510BINDING SITE FOR RESIDUE PO4 D 502
04AC4SOFTWAREARG D:133 , GLY E:90 , SER E:91 , THR E:92 , HOH E:508 , HOH E:510BINDING SITE FOR RESIDUE PO4 E 503
05AC5SOFTWAREGLY A:90 , SER A:91 , THR A:92 , HOH A:505 , ARG E:133BINDING SITE FOR RESIDUE PO4 A 504
06AC6SOFTWARETYR A:27 , ASN A:28 , GLY A:61 , SER A:62 , TRP A:63 , GLU A:64 , VAL A:86 , LEU A:87 , ILE A:88 , HIS A:94 , HOH A:506 , ILE E:118 , LEU E:119BINDING SITE FOR RESIDUE LMZ A 300
07AC7SOFTWAREILE A:118 , LEU A:119 , TYR B:27 , ASN B:28 , GLY B:61 , SER B:62 , TRP B:63 , GLU B:64 , VAL B:86 , LEU B:87 , ILE B:88 , HIS B:94 , HOH B:503BINDING SITE FOR RESIDUE LMZ B 301
08AC8SOFTWAREILE B:118 , LEU B:119 , TYR C:27 , ASN C:28 , GLY C:61 , SER C:62 , TRP C:63 , GLU C:64 , VAL C:86 , LEU C:87 , ILE C:88 , HIS C:94 , HOH C:504BINDING SITE FOR RESIDUE LMZ C 302
09AC9SOFTWAREILE C:118 , LEU C:119 , TYR D:27 , ASN D:28 , GLY D:61 , SER D:62 , TRP D:63 , GLU D:64 , VAL D:86 , LEU D:87 , ILE D:88 , HIS D:94 , HOH D:506 , HOH D:508BINDING SITE FOR RESIDUE LMZ D 303
10BC1SOFTWAREILE D:118 , LEU D:119 , TYR E:27 , ASN E:28 , GLY E:61 , SER E:62 , TRP E:63 , GLU E:64 , VAL E:86 , LEU E:87 , ILE E:88 , HIS E:94 , HOH E:506 , HOH E:509BINDING SITE FOR RESIDUE LMZ E 304

(-) SS Bonds  (0, 0)

(no "SS Bond" information available for 2A59)

(-) Cis Peptide Bonds  (0, 0)

(no "Cis Peptide Bond" information available for 2A59)

 Sequence-Structure Mapping

(-) SAPs(SNPs)/Variants  (0, 0)

(no "SAP(SNP)/Variant" information available for 2A59)

(-) PROSITE Motifs  (0, 0)

(no "PROSITE Motif" information available for 2A59)

(-) Exons   (0, 0)

(no "Exon" information available for 2A59)

(-) Sequences/Alignments

Asymmetric/Biological Unit
   Reformat: Number of residues per line =  ('0' or empty: single-line sequence representation)
  Number of residues per labelling interval =   
  UniProt sequence: complete  aligned part    
   Show mapping: SCOP domains CATH domains Pfam domains Secondary structure (by author)
SAPs(SNPs) PROSITE motifs Exons
(details for a mapped element are shown in a popup box when the mouse pointer rests over it)
Chain A from PDB  Type:PROTEIN  Length:146
 aligned with RIB4_SCHPO | Q9UUB1 from UniProtKB/Swiss-Prot  Length:159

    Alignment length:146
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      
           RIB4_SCHPO    13 LKGPELRILIVHARWNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
               SCOP domains d2a59a_ A: automated matches                                                                                                                       SCOP domains
               CATH domains 2a59A00 A:13-158  [code=3.40.50.960, no name defined]                                                                                              CATH domains
               Pfam domains -------------------------------------------------------------------------------------------------------------------------------------------------- Pfam domains
         Sec.struct. author .......eeeeee..hhhhhhhhhhhhhhhhhhhhh.hhh.eeeeee...hhhhhhhhhhhhhh...eeeeeeeee....hhhhhhhhhhhhhhhhhhhhhh..eeeeeeee.hhhhhhhhh......hhhhhhhhhhhhhhhhhh Sec.struct. author
                 SAPs(SNPs) -------------------------------------------------------------------------------------------------------------------------------------------------- SAPs(SNPs)
                    PROSITE -------------------------------------------------------------------------------------------------------------------------------------------------- PROSITE
                 Transcript -------------------------------------------------------------------------------------------------------------------------------------------------- Transcript
                 2a59 A  13 LKGPELRILIVHARYNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      

Chain B from PDB  Type:PROTEIN  Length:146
 aligned with RIB4_SCHPO | Q9UUB1 from UniProtKB/Swiss-Prot  Length:159

    Alignment length:146
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      
           RIB4_SCHPO    13 LKGPELRILIVHARWNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
               SCOP domains d2a59b_ B: automated matches                                                                                                                       SCOP domains
               CATH domains 2a59B00 B:13-158  [code=3.40.50.960, no name defined]                                                                                              CATH domains
               Pfam domains -------------------------------------------------------------------------------------------------------------------------------------------------- Pfam domains
         Sec.struct. author .......eeeeee..hhhhhhhhhhhhhhhhhhhhh.hhh.eeeeee...hhhhhhhhhhhhhh...eeeeeeeee....hhhhhhhhhhhhhhhhhhhhhh..eeeeeeee.hhhhhhhhh......hhhhhhhhhhhhhhhhhh Sec.struct. author
                 SAPs(SNPs) -------------------------------------------------------------------------------------------------------------------------------------------------- SAPs(SNPs)
                    PROSITE -------------------------------------------------------------------------------------------------------------------------------------------------- PROSITE
                 Transcript -------------------------------------------------------------------------------------------------------------------------------------------------- Transcript
                 2a59 B  13 LKGPELRILIVHARYNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      

Chain C from PDB  Type:PROTEIN  Length:146
 aligned with RIB4_SCHPO | Q9UUB1 from UniProtKB/Swiss-Prot  Length:159

    Alignment length:146
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      
           RIB4_SCHPO    13 LKGPELRILIVHARWNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
               SCOP domains d2a59c_ C: automated matches                                                                                                                       SCOP domains
               CATH domains 2a59C00 C:13-158  [code=3.40.50.960, no name defined]                                                                                              CATH domains
               Pfam domains -------------------------------------------------------------------------------------------------------------------------------------------------- Pfam domains
         Sec.struct. author .......eeeeee..hhhhhhhhhhhhhhhhhhhhh.hhh.eeeeee...hhhhhhhhhhhhhh...eeeeeeeee....hhhhhhhhhhhhhhhhhhhhhh..eeeeeeee.hhhhhhhhh......hhhhhhhhhhhhhhhhhh Sec.struct. author
                 SAPs(SNPs) -------------------------------------------------------------------------------------------------------------------------------------------------- SAPs(SNPs)
                    PROSITE -------------------------------------------------------------------------------------------------------------------------------------------------- PROSITE
                 Transcript -------------------------------------------------------------------------------------------------------------------------------------------------- Transcript
                 2a59 C  13 LKGPELRILIVHARYNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      

Chain D from PDB  Type:PROTEIN  Length:146
 aligned with RIB4_SCHPO | Q9UUB1 from UniProtKB/Swiss-Prot  Length:159

    Alignment length:146
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      
           RIB4_SCHPO    13 LKGPELRILIVHARWNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
               SCOP domains d2a59d_ D: automated matches                                                                                                                       SCOP domains
               CATH domains 2a59D00 D:13-158  [code=3.40.50.960, no name defined]                                                                                              CATH domains
               Pfam domains -------------------------------------------------------------------------------------------------------------------------------------------------- Pfam domains
         Sec.struct. author .......eeeeee..hhhhhhhhhhhhhhhhhhhhh.hhh.eeeeee.hhhhhhhhhhhhhhhh...eeeeeeeee....hhhhhhhhhhhhhhhhhhhhhh..eeeeeeee.hhhhhhhhh......hhhhhhhhhhhhhhhhhh Sec.struct. author
                 SAPs(SNPs) -------------------------------------------------------------------------------------------------------------------------------------------------- SAPs(SNPs)
                    PROSITE -------------------------------------------------------------------------------------------------------------------------------------------------- PROSITE
                 Transcript -------------------------------------------------------------------------------------------------------------------------------------------------- Transcript
                 2a59 D  13 LKGPELRILIVHARYNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      

Chain E from PDB  Type:PROTEIN  Length:146
 aligned with RIB4_SCHPO | Q9UUB1 from UniProtKB/Swiss-Prot  Length:159

    Alignment length:146
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      
           RIB4_SCHPO    13 LKGPELRILIVHARWNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
               SCOP domains d2a59e_ E: automated matches                                                                                                                       SCOP domains
               CATH domains 2a59E00 E:13-158  [code=3.40.50.960, no name defined]                                                                                              CATH domains
               Pfam domains -------------------------------------------------------------------------------------------------------------------------------------------------- Pfam domains
         Sec.struct. author .......eeeeee..hhhhhhhhhhhhhhhhhhhhh.hhh.eeeeee...hhhhhhhhhhhhhh...eeeeeeeee....hhhhhhhhhhhhhhhhhhhhhh..eeeeeeee.hhhhhhhhh......hhhhhhhhhhhhhhhhhh Sec.struct. author
                 SAPs(SNPs) -------------------------------------------------------------------------------------------------------------------------------------------------- SAPs(SNPs)
                    PROSITE -------------------------------------------------------------------------------------------------------------------------------------------------- PROSITE
                 Transcript -------------------------------------------------------------------------------------------------------------------------------------------------- Transcript
                 2a59 E  13 LKGPELRILIVHARYNLQAIEPLVKGAVETMIEKHDVKLENIDIESVPGSWELPQGIRASIARNTYDAVIGIGVLIKGSTMHFEYISEAVVHGLMRVGLDSGVPVILGLLTVLNEEQALYRAGLNGGHNHGNDWGSAAVEMGLKAL 158
                                    22        32        42        52        62        72        82        92       102       112       122       132       142       152      

   Legend:   → Mismatch (orange background)
  - → Gap (green background, '-', border residues have a numbering label)
    → Modified Residue (blue background, lower-case, 'x' indicates undefined single-letter code, labelled with number + name)
  x → Chemical Group (purple background, 'x', labelled with number + name, e.g. ACE or NH2)
  extra numbering lines below/above indicate numbering irregularities and modified residue names etc., number ends below/above '|'

 Classification and Annotation

(-) SCOP Domains  (1, 5)

Asymmetric/Biological Unit

(-) CATH Domains  (1, 5)

Asymmetric/Biological Unit
(-)
Class: Alpha Beta (26913)

(-) Pfam Domains  (0, 0)

(no "Pfam Domain" information available for 2A59)

(-) Gene Ontology  (9, 9)

Asymmetric/Biological Unit(hide GO term definitions)
Chain A,B,C,D,E   (RIB4_SCHPO | Q9UUB1)
molecular function
    GO:0000906    6,7-dimethyl-8-ribityllumazine synthase activity    Catalysis of the reaction: 3,4-dihydroxy-2-butanone-4-phosphate + 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione = 6,7-dimethyl-8-ribityllumazine + phosphate.
    GO:0005515    protein binding    Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
    GO:1902444    riboflavin binding    Interacting selectively and non-covalently with riboflavin.
    GO:0016740    transferase activity    Catalysis of the transfer of a group, e.g. a methyl group, glycosyl group, acyl group, phosphorus-containing, or other groups, from one compound (generally regarded as the donor) to another compound (generally regarded as the acceptor). Transferase is the systematic name for any enzyme of EC class 2.
biological process
    GO:0009231    riboflavin biosynthetic process    The chemical reactions and pathways resulting in the formation of riboflavin (vitamin B2), the precursor for the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).
cellular component
    GO:0005737    cytoplasm    All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.
    GO:0005758    mitochondrial intermembrane space    The region between the inner and outer lipid bilayers of the mitochondrial envelope.
    GO:0005634    nucleus    A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.
    GO:0009349    riboflavin synthase complex    An flavoprotein that catalyzes the reaction the breakdown of dimethyl(ribityl)lumazine to form riboflavin and ribitylamino-amino-dihydroxypyrimidine.

 Visualization

(-) Interactive Views

Asymmetric/Biological Unit
  Complete Structure
    Jena3D(integrated viewing of ligand, site, SAP, PROSITE, SCOP information)
    WebMol | AstexViewer[tm]@PDBe
(Java Applets, require no local installation except for Java; loading may be slow)
    STRAP
(Java WebStart application, automatic local installation, requires Java; full application with system access!)
    RasMol
(require local installation)
    Molscript (VRML)
(requires installation of a VRML viewer; select preferred view via VRML and generate a mono or stereo PDF format file)
 
  Ligands, Modified Residues, Ions
    LMZ  [ RasMol | Jena3D ]  +environment [ RasMol | Jena3D ]
    PO4  [ RasMol | Jena3D ]  +environment [ RasMol | Jena3D ]
 
  Sites
    AC1  [ RasMol ]  +environment [ RasMol ]
    AC2  [ RasMol ]  +environment [ RasMol ]
    AC3  [ RasMol ]  +environment [ RasMol ]
    AC4  [ RasMol ]  +environment [ RasMol ]
    AC5  [ RasMol ]  +environment [ RasMol ]
    AC6  [ RasMol ]  +environment [ RasMol ]
    AC7  [ RasMol ]  +environment [ RasMol ]
    AC8  [ RasMol ]  +environment [ RasMol ]
    AC9  [ RasMol ]  +environment [ RasMol ]
    BC1  [ RasMol ]  +environment [ RasMol ]
 
  Cis Peptide Bonds
(no "Cis Peptide Bonds" information available for 2a59)
 

(-) Still Images

Jmol
  protein: cartoon or spacefill or dots and stick; nucleic acid: cartoon and stick; ligands: spacefill; active site: stick
Molscript
  protein, nucleic acid: cartoon; ligands: spacefill; active site: ball and stick

 Databases and Analysis Tools

(-) Databases

Access by PDB/NDB ID
  2a59
    Family and Domain InformationProDom | SYSTERS
    General Structural InformationGlycoscienceDB | MMDB | NDB | OCA | PDB | PDBe | PDBj | PDBsum | PDBWiki | PQS | PROTEOPEDIA
    Orientation in MembranesOPM
    Protein SurfaceSURFACE
    Secondary StructureDSSP (structure derived) | HSSP (homology derived)
    Structural GenomicsGeneCensus
    Structural NeighboursCE | VAST
    Structure ClassificationCATH | Dali | SCOP
    Validation and Original DataBMRB Data View | BMRB Restraints Grid | EDS | PROCHECK | RECOORD | WHAT_CHECK
 
Access by UniProt ID/Accession number
  RIB4_SCHPO | Q9UUB1
    Comparative Protein Structure ModelsModBase
    Genomic InformationEnsembl
    Protein-protein InteractionDIP
    Sequence, Family and Domain InformationInterPro | Pfam | SMART | UniProtKB/SwissProt
 
Access by Enzyme Classificator   (EC Number)
  2.5.1.78
    General Enzyme InformationBRENDA | EC-PDB | Enzyme | IntEnz
    PathwayKEGG | MetaCyc
 
Access by Disease Identifier   (MIM ID)
  (no 'MIM ID' available)
    Disease InformationOMIM
 
Access by GenAge ID
  (no 'GenAge ID' available)
    Age Related InformationGenAge

(-) Analysis Tools

Access by PDB/NDB ID
    Domain InformationXDom
    Interatomic Contacts of Structural UnitsCSU
    Ligand-protein ContactsLPC
    Protein CavitiescastP
    Sequence and Secondary StructurePDBCartoon
    Structure AlignmentSTRAP(Java WebStart application, automatic local installation, requires Java; full application with system access!)
    Structure and Sequence BrowserSTING
 
Access by UniProt ID/Accession number
  RIB4_SCHPO | Q9UUB1
    Protein Disorder PredictionDisEMBL | FoldIndex | GLOBPLOT (for more information see DisProt)

 Related Entries

(-) Entries Sharing at Least One Protein Chain (UniProt ID)

UniProtKB/Swiss-Prot
        RIB4_SCHPO | Q9UUB11kyv 1kyx 1kyy 1kz1 1kz4 1kz6 1kz9 2a57 2a58

(-) Related Entries Specified in the PDB File

1kyv STRUCTURE OF 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE FROM SCHIZOSACCHAROMYCES POMBE WITH BOUND RIBOFLAVIN
1kyy STRUCTURE OF 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE FROM SCHIZOSACCHAROMYCES POMBE WITH BOUND LIGAND 5-NITRO-6-(D- RIBITYLAMINO)-2,4(1H,3H)-PYRIMIDINEDIONE
2a57 STRUCTURE OF 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE FROM SCHIZOSACCHAROMYCES POMBE MUTANT W27Y WITH BOUND LIGAND 6- CARBOXYETHYL-7-OXO-8-RIBITYLLUMAZINE
2a58 STRUCTURE OF 6,7-DIMETHYL-8-RIBITYLLUMAZINE SYNTHASE FROM SCHIZOSACCHAROMYCES POMBE MUTANT W27Y WITH BOUND LIGAND RIBOFLAVIN