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Q12062 (AFLK_ASPPA) Reviewed, UniProtKB/Swiss-Prot

Last modified June 11, 2014. Version 76. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Versicolorin B synthase

EC=4.2.1.143
Alternative name(s):
5'-oxoaverantin cyclase
EC=4.2.1.142
Aflatoxin biosynthesis protein K
Gene names
Name:vbs
Synonyms:aflK
OrganismAspergillus parasiticus
Taxonomic identifier5067 [NCBI]
Taxonomic lineageEukaryotaFungiDikaryaAscomycotaPezizomycotinaEurotiomycetesEurotiomycetidaeEurotialesAspergillaceaeAspergillus

Protein attributes

Sequence length643 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Catalyzes 2 dehydration steps in the aflatoxin biosynthesis pathway: (1) acts as an 5'-oxoaverantin cyclase that mediates conversion of 5'-oxoaverantin (OAVN) to (2'S,5'S)-averufin (AVR) and (2) acts as a versicolorin B synthase by catalyzing conversion of versiconal (VHOH) to versicolorin B (VB). Ref.1 Ref.3 Ref.4 Ref.5 Ref.7

Catalytic activity

Versiconal = versicolorin B + H2O. Ref.3 Ref.4 Ref.5 Ref.7

5'-oxoaverantin = (1'S,5'S)-averufin + H2O. Ref.3 Ref.4 Ref.5 Ref.7

Cofactor

FAD By similarity.

Pathway

Mycotoxin biosynthesis; aflatoxin biosynthesis. Ref.2

Subunit structure

Homodimer. Ref.1 Ref.3 Ref.5 Ref.7

Subcellular location

Cytoplasmcytosol Probable Ref.3.

Post-translational modification

N-glycosylated. Ref.6

Sequence similarities

Belongs to the GMC oxidoreductase family.

Biophysicochemical properties

Kinetic parameters:

KM=20 µM for 5'-oxoaverantin Ref.4 Ref.7

KM=3.1 µM for versiconal (at pH 6.0 and 30 degrees Celsius)

Vmax=6.67 nmol/min/mg enzyme with 5'-oxoaverantin as substrate

Vmax=0.15 µmol/min/mg enzyme with versiconal (at pH 6.0 and 30 degrees Celsius) as substrate

pH dependence:

Optimum pH is 5.5.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Propeptide1 – 4141
PRO_0000424163
Chain22 – 643622Versicolorin B synthase
PRO_0000424164

Regions

Nucleotide binding76 – 10530FAD By similarity

Amino acid modifications

Glycosylation1161N-linked (GlcNAc...) Potential
Glycosylation2211N-linked (GlcNAc...) Potential
Glycosylation5071N-linked (GlcNAc...) Potential

Sequences

Sequence LengthMass (Da)Tools
Q12062 [UniParc].

Last modified November 1, 1996. Version 1.
Checksum: 4B903BA6A0F39D11

FASTA64370,271
        10         20         30         40         50         60 
MGRNWFQVTA MAVVPVVGIM AAVNPTILSS AASSLPSLGA MFTSDDFASQ MDGRIQAQGL 

        70         80         90        100        110        120 
LSSHFGMYGW PGQSFDYVIV GGGTAGLAMA RRLSQDGTAS VAVIEAGGFY ETDAGNATEV 

       130        140        150        160        170        180 
PMYLFNYFFD NGKVKNPLFD WYQYTTPQPG LAQREMFYMQ GKTLGGSTAR GAMLYHRGSK 

       190        200        210        220        230        240 
GAYDMWADHV GDDSYRWDKW LPYFQKSVHF SGPETNPRPA NATALNDNTA FTASGGPVHV 

       250        260        270        280        290        300 
GYPFQVNAIS SWVDRALAKM GFPEAQGFSN GNLLGRSYIT HTINPYTRRR ETASSSYLRE 

       310        320        330        340        350        360 
ALMESNNLNI FTRTLVKRVL FDDQNRATGV TVNTDGFEWQ IGARKEVILS AGVMRSPQLL 

       370        380        390        400        410        420 
MVSGIGPKDH LEQLGIPVRS DLSGVGQNMQ DTIILGPTVP VKVESHSQLM GNKETLPRAI 

       430        440        450        460        470        480 
REYNEQRKGL LTNPGQDYFA FEKHQPGMLK ESTAADIDAA FPDDWPTFSY IALDDTFVPQ 

       490        500        510        520        530        540 
YDGKNYFSMS AALMTPFSRG TVTINSNDTA NPPIVDPQWL ADPRDQEMAV AAFRRCREIV 

       550        560        570        580        590        600 
ASDVMREVVA GPEILPGPQY QTDEEILNYI AETSDAYYAG VGTCAMGKAD DPKAVVDSKA 

       610        620        630        640 
RVLGVKGLRI VDASIFPFAI DGQPMGTVYA LAEKIAAEMM AGQ 

« Hide

References

[1]"Isolation and characterization of the versicolorin B synthase gene from Aspergillus parasiticus. Expansion of the aflatoxin b1 biosynthetic gene cluster."
Silva J.C., Minto R.E., Barry C.E., Holland K.A., Townsend C.A.
J. Biol. Chem. 271:13600-13608(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA], PROTEIN SEQUENCE OF 163-180 AND 414-428, FUNCTION, SUBUNIT.
Strain: ATCC 56775 / NRRL 5862 / Su-1 / SRRC 143.
[2]"Completed sequence of aflatoxin pathway gene cluster in Aspergillus parasiticus."
Yu J., Bhatnagar D., Cleveland T.E.
FEBS Lett. 564:126-130(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PATHWAY.
Strain: ATCC 56775 / NRRL 5862 / Su-1 / SRRC 143.
[3]"Aspergillus parasiticus cyclase catalyzes two dehydration steps in aflatoxin biosynthesis."
Sakuno E., Wen Y., Hatabayashi H., Arai H., Aoki C., Yabe K., Nakajima H.
Appl. Environ. Microbiol. 71:2999-3006(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE OF 41-66, FUNCTION, CATALYTIC ACTIVITY, SUBCELLULAR LOCATION, SUBUNIT.
[4]"Purification and properties of versiconal cyclase from Aspergillus parasiticus."
Lin B.K., Anderson J.A.
Arch. Biochem. Biophys. 293:67-70(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES.
Strain: ATCC 56775 / NRRL 5862 / Su-1 / SRRC 143.
[5]"Purification and characterization of versicolorin B synthase from Aspergillus parasiticus. Catalysis of the stereodifferentiating cyclization in aflatoxin biosynthesis essential to DNA interaction."
McGuire S.M., Silva J.C., Casillas E.G., Townsend C.A.
Biochemistry 35:11470-11486(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, CATALYTIC ACTIVITY, SUBUNIT.
[6]"Heterologous expression, isolation, and characterization of versicolorin B synthase from Aspergillus parasiticus. A key enzyme in the aflatoxin B1 biosynthetic pathway."
Silva J.C., Townsend C.A.
J. Biol. Chem. 272:804-813(1997) [PubMed] [Europe PMC] [Abstract]
Cited for: GLYCOSYLATION.
Strain: ATCC 56775 / NRRL 5862 / Su-1 / SRRC 143.
[7]"Involvement of two cytosolic enzymes and a novel intermediate, 5'-oxoaverantin, in the pathway from 5'-hydroxyaverantin to averufin in aflatoxin biosynthesis."
Sakuno E., Yabe K., Nakajima H.
Appl. Environ. Microbiol. 69:6418-6426(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, SUBUNIT.
[8]"Clustered pathway genes in aflatoxin biosynthesis."
Yu J., Chang P.K., Ehrlich K.C., Cary J.W., Bhatnagar D., Cleveland T.E., Payne G.A., Linz J.E., Woloshuk C.P., Bennett J.W.
Appl. Environ. Microbiol. 70:1253-1262(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.
Strain: ATCC 56775 / NRRL 5862 / Su-1 / SRRC 143.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
U51327 Genomic DNA. Translation: AAC49318.1.
U51328 mRNA. Translation: AAC49319.1.
AY371490 Genomic DNA. Translation: AAS66012.1.

3D structure databases

ProteinModelPortalQ12062.
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Enzyme and pathway databases

BioCycMetaCyc:MONOMER-14040.
UniPathwayUPA00287.

Family and domain databases

InterProIPR012132. GMC_OxRdtase.
IPR000172. GMC_OxRdtase_N.
IPR007867. GMC_OxRtase_C.
[Graphical view]
PfamPF05199. GMC_oxred_C. 1 hit.
PF00732. GMC_oxred_N. 1 hit.
[Graphical view]
PIRSFPIRSF000137. Alcohol_oxidase. 1 hit.
ProtoNetSearch...

Entry information

Entry nameAFLK_ASPPA
AccessionPrimary (citable) accession number: Q12062
Entry history
Integrated into UniProtKB/Swiss-Prot: October 16, 2013
Last sequence update: November 1, 1996
Last modified: June 11, 2014
This is version 76 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programFungal Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

PATHWAY comments

Index of metabolic and biosynthesis pathways