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Q8K9P7 (TOP1_BUCAP) Reviewed, UniProtKB/Swiss-Prot

Last modified May 1, 2013. Version 81. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
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Names and origin

Protein namesRecommended name:
DNA topoisomerase 1
EC=5.99.1.2
Alternative name(s):
DNA topoisomerase I
Omega-protein
Relaxing enzyme
Swivelase
Untwisting enzyme
Gene names
Name:topA
Ordered Locus Names:BUsg_273
OrganismBuchnera aphidicola subsp. Schizaphis graminum (strain Sg) [Complete proteome] [HAMAP]
Taxonomic identifier198804 [NCBI]
Taxonomic lineageBacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Buchnera ›

Protein attributes

Sequence length853 AA.
Sequence statusComplete.
Protein existenceInferred from homology

General annotation (Comments)

Function

Releases the supercoiling and torsional tension of DNA, which is introduced during the DNA replication and transcription, by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(5'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand, thus removing DNA supercoils. Finally, in the religation step, the DNA 3'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone By similarity.

Catalytic activity

ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.

Cofactor

Magnesium. Binds two Mg2+ per subunit By similarity.

Subunit structure

Monomer By similarity.

Sequence similarities

Belongs to the type IA topoisomerase family.

Contains 1 Toprim domain.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 853853DNA topoisomerase 1
PRO_0000145145

Regions

Domain3 – 136134Toprim
Zinc finger589 – 62133C4-type 1
Zinc finger649 – 67628C4-type 2
Zinc finger699 – 72426C4-type 3
Region186 – 1916Interaction with DNA By similarity

Sites

Active site3131O-(5'-phospho-DNA)-tyrosine intermediate By similarity
Metal binding91Magnesium 1; catalytic By similarity
Metal binding1051Magnesium 1; catalytic By similarity
Metal binding1051Magnesium 2 By similarity
Metal binding1071Magnesium 2 By similarity
Site331Interaction with DNA By similarity
Site1621Interaction with DNA By similarity
Site1631Interaction with DNA By similarity
Site1661Interaction with DNA By similarity
Site1711Interaction with DNA By similarity
Site1781Interaction with DNA By similarity
Site3151Interaction with DNA By similarity

Sequences

Sequence LengthMass (Da)Tools
Q8K9P7 [UniParc].

Last modified October 1, 2002. Version 1.
Checksum: 99B454AB78AC6D1B

FASTA85398,816
        10         20         30         40         50         60 
MCKSLVIVES PVKAKTISKY LGKQYIVKSS VGHVRDLINN KSKNKKNIKK SNIKHNEKTA 

        70         80         90        100        110        120 
LIQQMGINPY KNWKAEYHIL PGKEKIISEL KNIANKVHYI YLATDLDREG EAIAWHLKEV 

       130        140        150        160        170        180 
IGGNSLKFRR VVFNEITKKS IEKAFQNIGK INMNRVYSQQ ARRFMDRIVG YMISPLLWKK 

       190        200        210        220        230        240 
ISRGLSAGRV QSAAVRLITD REYEIKNFIE REHWKISLSL LSKENKKVTM DITHYRNKTF 

       250        260        270        280        290        300 
LLNNKKEVNS TIEKIKNLSF IITDRKDKIF KKKPPAPLIT STLQQASNID LGFSVKKTMF 

       310        320        330        340        350        360 
LAQKLYEQGY ITYIRTDSYF LSNYAIEKVR SYIENFYGSD FLPKKSNIYS NQKYSQEAHE 

       370        380        390        400        410        420 
AIRPSDVQVV NIDNCDPDAK KLYKLIWNYF IASQMKSERY KSIKTTVMAD VFKLQSNTKI 

       430        440        450        460        470        480 
VLFSGWTKIL KKSNNVNFKF PVLDIGTTLI LDKILPHQIF TKPPPRFSES SLVRELEKKG 

       490        500        510        520        530        540 
IGRPSTYATI ITKIKEKGYL KIKKNKFYAA KIGEILITRL KKNFSDLVDY DFTARMEKNL 

       550        560        570        580        590        600 
DQVSDKLINW KHLLNSFFDN FSQQLEQAKK PPEEGGMELN TTVPTEIDCS LCNKKMGIKT 

       610        620        630        640        650        660 
AVTGVFLSCL GYNSEPNEKR CKNTINLISL NDLSTTKKEE KNFHLKNRCK KCNLVMDVYL 

       670        680        690        700        710        720 
INENLKIFIC INNPSCNGYN LKKGIFKKSL NCSLKKIKCE KCKNDMLFKT GRFGNFFMCI 

       730        740        750        760        770        780 
NDTCKNTRKI LPNGEISEPK FEPIPFPDIL CEKSNTWFVL REGISGIFFA ANTFPKSRET 

       790        800        810        820        830        840 
RSPFVEELAR FEYLLPKKLH YLASAPQRDN KGNKTIVCFN KLNKQQYIAS KKEGKFTGWA 

       850 
AFFIDRKWCI VNK

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References

[1]"50 million years of genomic stasis in endosymbiotic bacteria."
Tamas I., Klasson L., Canbaeck B., Naeslund A.K., Eriksson A.-S., Wernegreen J.J., Sandstroem J.P., Moran N.A., Andersson S.G.E.
Science 296:2376-2379(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: Sg.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ		AE013218 Genomic DNA. Translation: AAM67831.1.
RefSeqNP_660620.1. NC_004061.1.

3D structure databases

ProteinModelPortalQ8K9P7.
SMRQ8K9P7. Positions 3-562, 733-848.
ModBaseSearch...

Protein-protein interaction databases

STRING198804.BUsg273.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaAAM67831; AAM67831; BUsg_273.
GeneID1005477.
KEGGbas:BUsg273.
PATRIC21247351. VBIBucAph100086_0285.

Organism-specific databases

CMRSearch...

Phylogenomic databases

eggNOGCOG0551.
KOK03168.
OMAEFWDIHA.
ProtClustDBPRK07561.

Enzyme and pathway databases

BioCycBAPH198804:GHMG-333-MONOMER.

Family and domain databases

Gene3D1.10.290.10. 1 hit.
1.10.460.10. 2 hits.
HAMAPMF_00952. Topoisom_1_prok.
InterProIPR000380. Topo_IA.
IPR003601. Topo_IA_2.
IPR023406. Topo_IA_AS.
IPR013497. Topo_IA_cen.
IPR013824. Topo_IA_cen_sub1.
IPR013826. Topo_IA_cen_sub3.
IPR023405. Topo_IA_core_domain.
IPR003602. Topo_IA_DNA-bd.
IPR013498. Topo_IA_Znf.
IPR005733. TopoI_bac-type.
IPR013263. TopoI_Znr_bac.
IPR006171. Toprim_domain.
[Graphical view]
PANTHERPTHR11390. PTHR11390. 1 hit.
PfamPF08272. Topo_Zn_Ribbon. 2 hits.
PF01131. Topoisom_bac. 1 hit.
PF01751. Toprim. 1 hit.
PF01396. zf-C4_Topoisom. 1 hit.
[Graphical view]
PRINTSPR00417. PRTPISMRASEI.
SMARTSM00437. TOP1Ac. 1 hit.
SM00436. TOP1Bc. 1 hit.
SM00493. TOPRIM. 1 hit.
[Graphical view]
SUPFAMSSF56712. Topo_IA_core. 1 hit.
TIGRFAMsTIGR01051. topA_bact. 1 hit.
PROSITEPS00396. TOPOISOMERASE_I_PROK. 1 hit.
PS50880. TOPRIM. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry nameTOP1_BUCAP
AccessionPrimary (citable) accession number: Q8K9P7
Entry history
Integrated into UniProtKB/Swiss-Prot: November 8, 2002
Last sequence update: October 1, 2002
Last modified: May 1, 2013
This is version 81 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Relevant documents

Buchnera aphidicola (subsp. Schizaphis graminum)

Buchnera aphidicola (subsp. Schizaphis graminum): entries and gene names

SIMILARITY comments

Index of protein domains and families

to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·Documents