P34185 (TOP1_SYNE7) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended 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:	Synpcc7942_1416

Organism

Synechococcus elongatus (strain PCC 7942) (Anacystis nidulans R2) [Complete proteome] [HAMAP]

Taxonomic identifier

1140 [NCBI]

Taxonomic lineage

Bacteria › Cyanobacteria › Chroococcales › Synechococcus

Protein attributes

Sequence length	883 AA.
Sequence status	Complete.
Protein existence	Inferred from homology

General annotation (Comments)

Function	Releases the supercoiling and torsional tension of DNA 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 than 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.
Subunit structure	Monomer.
Sequence similarities	Belongs to the type IA topoisomerase family. Contains 1 Toprim domain.
Sequence caution	The sequence CAA51086.1 differs from that shown. Reason: Frameshift at several positions.

Ontologies

Keywords
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
Cellular component	chromosome Inferred from electronic annotation. Source: InterPro
Molecular function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW 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 – 883	883	DNA topoisomerase 1		PRO_0000145167
Regions
	Domain	2 – 124	123	Toprim
Sites
	Active site	320	1	O-(5'-phospho-DNA)-tyrosine intermediate By similarity
Experimental info
	Sequence conflict	101 – 102	2	ES → KV in CAA51086. Ref.1
	Sequence conflict	392	1	L → V in CAA51086. Ref.1

Sequences

	Sequence		Length	Mass (Da)
	P34185 [UniParc]. Last modified April 18, 2006. Version 2. Checksum: C90DAC6EE1202B9A	FASTA	883	98,296
	10 20 30 40 50 60 MPKLVIVESP TKARTIRNYL PKDYRVEASM GHVRDLPQSA SDIPTELKGE KWSNLGVDVE 70 80 90 100 110 120 NNFAPLYIVP KDKKKIVKTL KDALKDADEL ILATDEDREG ESISWHLLQL LQPRVPTKRM 130 140 150 160 170 180 VFHEITQEAI QAALKNCRDV DQRLVHAQET RRILDRLVGY TLSPLLWKKI AWGLSAGRVQ 190 200 210 220 230 240 SVAVRLLVQR ERARRAFRQG SYWDLKAQLT VEAGQFEAKL WTLAGQRLAT GNDFDESTGQ 250 260 270 280 290 300 IIAGRQVCLL DQQEAEALRD RLQTQPWQVK SLEEKPTTRK PAPPFTTSTL QQESNRKLRL 310 320 330 340 350 360 SARETMRVAQ SLYERGFITY MRTDSVHLSQ QAIEAARSCV EQMYGKNYLS PQPRQFTTKS 370 380 390 400 410 420 KNAQEAHEAI RPAGNTFRLP QETGLSGAEF ALYDLIWKRT IASQMAEARQ TMLSVLLEVD 430 440 450 460 470 480 NAEFRASGKR IDFPGFFRAY VEGSDDPDAA LEDREILLPA LKVGDRPTCQ ELAAIGHETQ 490 500 510 520 530 540 PPARYTEASL VKMLENEGIG RPSTYASIIG TIVDRGYAQL VSNTLTPTFT AFAVTALLEQ 550 560 570 580 590 600 HFPDLVDTSF SARMEQSLDD ISNGEVDWLP YLSQFYRGDR GLEEQVKLRE SEIDPAAART 610 620 630 640 650 660 VALEGLPAKV RIGRFGAYLE AEADGEPIKA NLPKELTPAD LDVQRVETLL RQKTEGPDQL 670 680 690 700 710 720 GTHPETDEPI YLLTGAYGPY VQLGAATEEK PKPKRASLPK GMSLETISLE QAVGLLSLPR 730 740 750 760 770 780 TLGEHPETGR RIQAGLGRFG PYVVCDLGGG EKDYRSLKAD DDVLTIDLDR ALELLAQPKK 790 800 810 820 830 840 SRGRGKEPIR EVGLHPDDQA PIQIFEGPYG LYLKHGKVNA SLPEDEKPET ISLETAVAAL 850 860 870 880 AAKAGQAKAK GGRRSTGTPK SGETKARTTK TTKKTTTRRT TSR

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"The genomic region of rbcLS in Synechococcus sp. PCC 7942 contains genes involved in the ability to grow under low CO2 concentration and in chlorophyll biosynthesis." Ronen-Tarazi M., Lieman-Hurwitz J., Gabay C., Orus M.I., Kaplan A. Plant Physiol. 108:1461-1469(1995) [PubMed: 7659748] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Complete sequence of chromosome 1 of Synechococcus elongatus PCC 7942." US DOE Joint Genome Institute Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina T., Hammon N., Israni S., Pitluck S., Schmutz J., Larimer F., Land M., Kyrpides N., Lykidis A., Richardson P. Submitted (AUG-2005) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: PCC 7942.

Cross-references

Sequence databases
EMBL GenBank DDBJ	X72391 Genomic DNA. Translation: CAA51086.1. Frameshift. CP000100 Genomic DNA. Translation: ABB57446.1.
PIR	S32158.
RefSeq	YP_400433.1. NC_007604.1.
3D structure databases
ProteinModelPortal	P34185.
ModBase	Search...
Protein-protein interaction databases
STRING	P34185.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	3774129.
GenomeReviews	Gene locus Synpcc7942_1416 in contig CP000100_GR.
KEGG	syf:Synpcc7942_1416.
PATRIC	23788179. VBISynElo51371_1616.
Organism-specific databases
CMR	Search...
Phylogenomic databases
eggNOG	COG0550.
HOGENOM	HBG512935.
PhylomeDB	P34185.
ProtClustDB	PRK07561.
Enzyme and pathway databases
BioCyc	SYNEL:SYNPCC7942_1416-MONOMER.
Family and domain databases
InterPro	IPR000380. Topo_IA. IPR003601. Topo_IA_2. IPR023406. Topo_IA_AS. IPR013497. Topo_IA_cen. IPR013824. Topo_IA_cen_sub1. IPR013825. Topo_IA_cen_sub2. IPR023405. Topo_IA_core_domain. IPR003602. Topo_IA_DNA-bd. IPR005733. TopoI_bac-type. IPR006171. Toprim_domain. [Graphical view]
Gene3D	G3DSA:1.10.460.10. Topo_IA_cen_sub1. 2 hits. G3DSA:2.70.20.10. Topo_IA_cen_sub2. 2 hits.
KO	K03168.
PANTHER	PTHR11390. Topo_IA. 1 hit.
Pfam	PF01131. Topoisom_bac. 1 hit. PF01751. Toprim. 1 hit. [Graphical view]
PRINTS	PR00417. PRTPISMRASEI.
SMART	SM00437. TOP1Ac. 1 hit. SM00436. TOP1Bc. 1 hit. SM00493. TOPRIM. 1 hit. [Graphical view]
SUPFAM	SSF56712. Topo_IA_core. 1 hit.
TIGRFAMs	TIGR01051. TopA_bact. 1 hit.
PROSITE	PS00396. TOPOISOMERASE_I_PROK. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

TOP1_SYNE7

Accession

Primary (citable) accession number: P34185
Secondary accession number(s): Q31NC3

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 1, 1994
Last sequence update:	April 18, 2006
Last modified:	January 25, 2012
This is version 82 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program