Reviewed, UniProtKB/Swiss-Prot Q7T6X9 (TOP1E_MIMIV)

Names and origin

Protein names

Recommended name:
    DNA topoisomerase 1B
      Short name=TopIB
    EC=5.99.1.2
Alternative name(s):
    DNA topoisomerase type IB

Gene names

Name:	TOP1E
Ordered Locus Names:	MIMI_R194

Organism

Acanthamoeba polyphaga mimivirus (APMV) [Complete proteome]

Taxonomic identifier

212035 [NCBI]

Taxonomic lineage

Viruses › dsDNA viruses, no RNA stage › Mimiviridae › Mimivirus

Virus host

Acanthamoeba polyphaga (Amoeba) [TaxID: 5757]

Protein attributes

Sequence length	336 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Relaxes supercoiled DNA. Modifies DNA topology by introducing reversible enzyme-linked breaks in the DNA phosphodiester backbone. This is accomplished by cleaving one strand of the DNA duplex and passing the intact complementary strand through the nick. Cleaves DNA after CCCTT sequence.
Catalytic activity	ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
Subunit structure	Monomer By similarity.
Subcellular location	Virion Ref.3.
Miscellaneous	When a topoisomerase transiently breaks a DNA backbone bond, it simultaneously forms a protein-DNA link, in which a tyrosyl oxygen in the enzyme is joined to a DNA phosphorus at one end of the enzyme-severed DNA strand By similarity.
Sequence similarities	Belongs to the eukaryotic type I topoisomerase family.

Ontologies

Keywords
Cellular component	Virion
Ligand	ATP-binding DNA-binding Nucleotide-binding
Molecular function	Isomerase Topoisomerase
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	DNA topological change Inferred from electronic annotation. Source: InterPro DNA unwinding during replication Inferred from electronic annotation. Source: InterPro
Cellular component	chromosome Inferred from electronic annotation. Source: InterPro virion Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW DNA topoisomerase (ATP-hydrolyzing) activity Inferred from electronic annotation. Source: InterPro DNA topoisomerase type I activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 336	336	DNA topoisomerase 1B		PRO_0000145212
Sites
	Active site	294	1	O-(3'-phospho-DNA)-tyrosine intermediate By similarity
Experimental info
	Mutagenesis	135	1	R → A: Complete loss of supercoil relaxation activity in vitro. Ref.2
	Mutagenesis	241	1	R → A: Complete loss of supercoil relaxation activity in vitro. Ref.2
	Mutagenesis	285	1	H → A: Partial loss of supercoil relaxation activity in vitro. Ref.2
	Mutagenesis	294	1	Y → A: Complete loss of supercoil relaxation activity in vitro. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	Q7T6X9-1 [UniParc]. Last modified December 7, 2004. Version 2. Checksum: 3C0A8CDE8D274FAB	FASTA	336	39,879
	10 20 30 40 50 60 MSYDEKHLME GIYREKSGDK FIYYYFDNNE EVTTKDIERI NKLRIPPAWT NVWVARDPNS 70 80 90 100 110 120 PIQAIGTDSK GRKQYRYNEI HIQGAEKEKF KRLYDFIKSI PKLEKAMVRD NNFPFYNKNR 130 140 150 160 170 180 VISLMLQMVR DYNMRVGKEV YARQNKSYGI SSLRKKHVKI SPGVITLNFK GKSGQRLNYT 190 200 210 220 230 240 IRNDFYIDGI KMLMKLEGDR LFQYISTDED GNEKIMRVND RDLNKYIQEN MGSEFTIKDF 250 260 270 280 290 300 RTFGANLYFI QALLSETRKR TPKNRKTIKK NIANAFKSTA RQLKHTGAVS KKSYVMNYTL 310 320 330 ELYQNNPEFF IEHKNDDPID FLLRILKSYR KDVLGE

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"The 1.2-megabase genome sequence of Mimivirus." Raoult D., Audic S., Robert C., Abergel C., Renesto P., Ogata H., La Scola B., Susan M., Claverie J.-M. Science 306:1344-1350(2004) [PubMed: 15486256] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: Rowbotham-Bradford.
[2]	"Characterization of mimivirus DNA topoisomerase IB suggests horizontal gene transfer between eukaryal viruses and bacteria." Benarroch D., Claverie J.-M., Raoult D., Shuman S. J. Virol. 80:314-321(2006) [PubMed: 16352556] [Abstract] Cited for: CHARACTERIZATION, MUTAGENESIS OF ARG-135; ARG-241; HIS-285 AND TYR-294. Strain: Rowbotham-Bradford.
[3]	"Mimivirus giant particles incorporate a large fraction of anonymous and unique gene products." Renesto P., Abergel C., Decloquement P., Moinier D., Azza S., Ogata H., Fourquet P., Gorvel J.-P., Claverie J.-M., Raoult D. J. Virol. 80:11678-11685(2006) [PubMed: 16971431] [Abstract] Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS], SUBCELLULAR LOCATION.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AY653733 Genomic DNA. Translation: AAQ09581.2.
RefSeq	YP_142548.1.
3D structure databases
SMR	Q7T6X9. Positions 35-306.
ModBase	Search...
Genome annotation databases
GeneID	3161989.
Enzyme and pathway databases
BRENDA	5.99.1.2. 281366.
Family and domain databases
InterPro	IPR011010. DNA_brk_join_enz. IPR001631. TopoI_C. IPR014711. TopoI_cat_a-hlx-sub_euk. [Graphical view]
Gene3D	G3DSA:3.90.15.10. TopoI_cat_a-hlx-sub_euk. 1 hit.
PRINTS	PR00416. EUTPISMRASEI.
PROSITE	PS00176. TOPOISOMERASE_I_EUK. False negative. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

TOP1E_MIMIV

Accession

Primary (citable) accession number: Q7T6X9

Entry history

Integrated into UniProtKB/Swiss-Prot:	September 13, 2005
Last sequence update:	December 7, 2004
Last modified:	February 9, 2010
This is version 34 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Virus (Virus annotation project)