Protein: Initiator protein NS1 (NS1) (EC 3.1.21.-) (EC 3.6.4.12) (NCVP1) (Non-capsid protein NS-1) (Non-structural protein 1) (Non-structural protein NS1) (Q9PZT1)
Organism: Human parvovirus B19 (strain HV) (HPV B19)
Function: Multifunctional protein essential for viral DNA replication, which cooperatively interacts with the viral DNA origin of replication and transactivates several promoters including the viral p6 promoter. Binds the origin of replication and performs an endonucleolytic nick within a conserved sequence in the viral genome, thereby initiating the rolling circle replication (RCR). Participates in the transcriptional regulation the viral p6 promoter that regulates all viral transcripts and the cellular CDN1A or IL6 promoters. Transactivates several host promoters some of which induce the S cell cycle phase for the production of host replicative proteins. Up-regulates the expression of host E2F4 and E2F5 and interacts with both these factors thereby inhibiting the host cell cycle G2/M transition. This arrest promotes apoptosis for viral release.
Subcellular location: Host nucleus {ECO:0000269|PubMed:20890043}.
Sequence: MELFRGVLQVSSNVLDCANDNWWCSLLDLDTSDWEPLTHTNRLMAIYLSSVASKLDFTGGPLAGCLYFFQVECNKFEEGYHIHVVIGGPGLNPRNLTVCVEGLFNNVLYHLVTENVKLKFLPGMTTKGKYFRDGEQFIENYLMKKIPLNVVWCVTNIDGYIDTCISATFRRGACHAKKPRITTAINDTSSDAGESSGTGAEVVPINGKGTKASIKFQTMVNWLCENRVFTEDKWKLVDFNQYTLLSSSHSGSFQIQSALKLAIYKATNLVPTSTFLLHTDFEQVMCIKDNKIVKLLLCQNYDPLLVGQHVLKWIDKKCGKKNTLWFYGPPSTGKTNLAMAIAKSVPVYGMVNWNNENFPFNDVAGKSLVVWDEGIIKSTIVEAAKAILGGQPTRVDQKMRGSVAVPGVPVVITSNGDITFVVSGNTTTTVHAKALKERMVKLNFTVRCSPDMGLLTEADVQQWLTWCNAQSWDHYENWAINYTFDFPGINADALHPDLQTTPIVTDTSISSSGGESSEELSESSFFNLITPGAWNTETPRSSTPIPGTSSGESFVGSSVSSEVVAASWEEAFYTPLADQFRELLVGVDYVWDGVRGLPVCCVQHINNSGGGLGLCPHCINVGAWYNGWKFREFTPDLVRCSCHVGASNPFSVLTCKKCAYLSGLQSFVDYE
InterPro domains: - IPR014835: NS1 nuclease, NS1-Nuc domain, parvovirinae (domain) [9-176]
- IPR027417: P-loop containing nucleoside triphosphate hydrolase (homologous_superfamily) [274-483]
- IPR001257: Parvovirus non-structural protein 1, helicase domain (domain) [210-485]
- IPR049901: NS1 nuclease, NS1-Nuc domain, Parvovirus (domain) [1-186]
- IPR014015: Helicase, superfamily 3, DNA virus (domain) [302-457]
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0005515 (protein binding)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0009987 (cellular process), GO:0016032 (viral process), GO:0009058 (biosynthetic process), GO:0044237 (cellular metabolic process), GO:0019058 (viral life cycle), GO:0071704 (organic substance metabolic process), GO:0044238 (primary metabolic process), GO:0006807 (nitrogen compound metabolic process), GO:0019079 (viral genome replication), GO:0044249 (cellular biosynthetic process), GO:0006725 (cellular aromatic compound metabolic process), GO:0034641 (cellular nitrogen compound metabolic process), GO:1901360 (organic cyclic compound metabolic process), GO:1901576 (organic substance biosynthetic process), GO:0039693 (viral DNA genome replication), GO:0006139 (nucleobase-containing compound metabolic process), GO:0044260 (cellular macromolecule metabolic process), GO:0043170 (macromolecule metabolic process), GO:0046483 (heterocycle metabolic process), GO:0006259 (DNA metabolic process), GO:0009059 (macromolecule biosynthetic process), GO:1901362 (organic cyclic compound biosynthetic process), GO:0044271 (cellular nitrogen compound biosynthetic process), GO:0090304 (nucleic acid metabolic process), GO:0034654 (nucleobase-containing compound biosynthetic process), GO:0019438 (aromatic compound biosynthetic process), GO:0018130 (heterocycle biosynthetic process), GO:0071897 (DNA biosynthetic process)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0018995 (host cellular component), GO:0043657 (host cell), GO:0033643 (host cell part), GO:0033646 (host intracellular part), GO:0043656 (host intracellular region), GO:0033647 (host intracellular organelle), GO:0033648 (host intracellular membrane-bounded organelle), GO:0042025 (host cell nucleus)