Reviewed, UniProtKB/Swiss-Prot Q912W1 (REP_CACV)

Names and origin

Protein names

Recommended name:
    Replication-associated protein
    EC=2.7.7.-
    EC=3.1.21.-
    EC=3.6.1.3
Alternative name(s):
    ATP-dependent helicase Rep
    RepP

Gene names

Name:	Rep
ORF Names:	ORF1

Organism

Canary circovirus (CaCV) [Complete proteome]

Taxonomic identifier

142661 [NCBI]

Taxonomic lineage

Viruses › ssDNA viruses › Circoviridae › Circovirus

Virus host

Serinus [TaxID: 9134]

Protein attributes

Sequence length	290 AA.
Sequence status	Complete.
Protein existence	Inferred from homology.

General annotation (Comments)

Function	Essential for the replication of viral ssDNA. The closed circular ssDNA genome is first converted to a superhelical dsDNA. Rep and/or Rep' binds a specific hairpin at the genome origin of replication. Introduces an endonucleolytic nick within the conserved sequence 5'-AGTATTAC-3' in the intergenic region of the genome, thereby initiating the rolling circle replication (RCR). Following cleavage, binds covalently to the 5'-phosphate of DNA as a tyrosyl ester. The cleavage gives rise to a free 3'-OH that serves as a primer for the cellular DNA polymerase. The polymerase synthesizes the (+) strand DNA by rolling circle mechanism. After one round of replication, a Rep-catalyzed nucleotidyl transfer reaction releases a circular single-stranded virus genome, thereby terminating the replication. Displays origin-specific DNA cleavage, nucleotidyl transferase, ATPase and helicase activities. ATPase activity is probably carried by the isoform Rep By similarity.
Catalytic activity	ATP + H2O = ADP + phosphate.
Cofactor	Divalent metal cations, possibly magnesium or manganese By similarity.
Subcellular location	Host nucleus Potential.
Domain	There are 3 rolling circle replication (RCR) motifs. RCR-2 is probably involved in metal coordination. RCR-3 is required for phosphodiester bond cleavage for initiation of RCR.
Sequence similarities	Belongs to the nanoviruses/circoviruses replication-associated protein family.

Ontologies

Keywords
Biological process	DNA replication
Cellular component	Host nucleus
Ligand	ATP-binding DNA-binding Metal-binding Nucleotide-binding
Molecular function	Endonuclease Helicase Hydrolase Nuclease Nucleotidyltransferase Transferase
PTM	Covalent protein-DNA linkage
Technical term	Complete proteome Multifunctional enzyme
Gene Ontology (GO)
Biological process	DNA replication Inferred from electronic annotation. Source: UniProtKB-KW protein-DNA covalent cross-linking Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	host cell nucleus Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW ATPase activity, uncoupled Inferred from electronic annotation. Source: EC DNA binding Inferred from electronic annotation. Source: UniProtKB-KW RNA binding Inferred from electronic annotation. Source: InterPro RNA helicase activity Inferred from electronic annotation. Source: InterPro endodeoxyribonuclease activity, producing 5'-phosphomonoesters Inferred from electronic annotation. Source: InterPro metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW nucleotidyltransferase activity Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 290	290	Replication-associated protein		PRO_0000319863
Regions
	Nucleotide binding	165 – 172	8	ATP By similarity
	Motif	4 – 13	10	Nuclear localization signal Potential
	Motif	14 – 17	4	RCR-1 By similarity
	Motif	51 – 56	6	RCR-2 By similarity
	Motif	60 – 80	21	Nuclear localization signal Potential
	Motif	89 – 92	4	RCR-3 By similarity
Sites
	Active site	89	1	For DNA cleavage activity By similarity
	Metal binding	43	1	Divalent metal cation Potential
	Metal binding	51	1	Divalent metal cation Potential
	Metal binding	93	1	Divalent metal cation Potential

Sequences

	Sequence		Length	Mass (Da)
	Q912W1-1 [UniParc]. Last modified June 1, 2002. Version 2. Checksum: 98095B2736B6B4C8	FASTA	290	33,372
	10 20 30 40 50 60 MAPVRAAAAK RWCFTLNNYT AEEEAKVRAL LPGEFHFAIC GKERGEQGTP HLQGFLHFKK 70 80 90 100 110 120 KQRLSALKKL LARAHWEKAR GSDHDNEEYC SKENDVILTI GEPVQGNRSD LAGAVAAVKA 130 140 150 160 170 180 GRRMVDIARE FSEIYVKYGR GLRDLALMIG QKPRDFKTEV VVITGPSGVG KSRLASEMEG 190 200 210 220 230 240 SKFYKMKGDW WDGYSNEDIV IMDDFYGWLP FCEMLRLMDR YPHKVPVKGS YVEFTSKKIV 250 260 270 280 290 ITSNTHPESW YCPDKCYLPA LFRRINKWMY WDGLRFEDVP DAMKKHPINY

References

[1]	"Nucleotide sequence-based identification of a novel circovirus of canaries." Todd D., Weston J., Ball N.W., Borghmans B.J., Smyth J.A., Gelmini L., Lavazza A. Avian Pathol. 30:321-325(2001) Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].

Cross-references

Sequence databases
EMBL GenBank DDBJ	AJ301633 Genomic DNA. Translation: CAC44748.2.
RefSeq	NP_573442.1.
3D structure databases
SMR	Q912W1. Positions 8-108.
ModBase	Search...
Genome annotation databases
GeneID	935131.
Enzyme and pathway databases
BRENDA	3.6.1.3. 313666.
Family and domain databases
InterPro	IPR000605. Helicase_SF3_ssDNA/RNA_vir. IPR003365. Viral_rep_N. [Graphical view]
Pfam	PF00910. RNA_helicase. 1 hit. PF02407. Viral_Rep. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

REP_CACV

Accession

Primary (citable) accession number: Q912W1

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 26, 2008
Last sequence update:	June 1, 2002
Last modified:	January 19, 2010
This is version 31 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Virus (Virus annotation project)