Annotations: 7NFR

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
B	V-set_8	e7nfrB1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_8	ECOD (1.6)
A	Flu_PB2_4th	e7nfrA2	A: alpha arrays	X: Helical domain in PB2 (From Topology)	H: Helical domain in PB2 (From Topology)	T: Helical domain in PB2	F: Flu_PB2_4th	ECOD (1.6)
A	Flu_PB2_5th	e7nfrA1	A: a+b three layers	X: Polymerase basic protein 2 cap-binding domain (From Topology)	H: Polymerase basic protein 2 cap-binding domain (From Topology)	T: Polymerase basic protein 2 cap-binding domain	F: Flu_PB2_5th	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B	2.60.40.10	Mainly Beta	Sandwich	Immunoglobulin-like	Immunoglobulins	CATH (utative)

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B	Heavy Chain	IGHV3	-	polymerase basic protein 2	SAbDab (2025-12-19)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00604	Influenza RNA polymerase PB2 CAP binding domain (Flu_PB2_5th)	Influenza RNA polymerase PB2 CAP binding domain	Influenza virus encodes a large, multidomain RNA-dependent RNA polymerase that can both transcribe and replicate the viral RNA genome. In influenza virus, the polymerase is composed of three polypeptides: PB1, PB2 and PA/P3. PB1 houses the polymerase ...	Influenza virus encodes a large, multidomain RNA-dependent RNA polymerase that can both transcribe and replicate the viral RNA genome. In influenza virus, the polymerase is composed of three polypeptides: PB1, PB2 and PA/P3. PB1 houses the polymerase active site, whereas PB2 and PA/P3 contain, respectively, cap-binding [1] and endonuclease domains required for transcription initiation by cap-snatching [2]. This entry represents the CAP binding domain [2].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
B	NB8194	-	-	-
A	Polymerase basic protein 2	RNA-directed RNA polymerase activity 5'-3' RNA polymerase activity catalytic activity, acting on RNA catalytic activity, acting on a nucleic acid RNA polymerase activity transferase activity nucleotidyltransferase activity catalytic activity transferase activity, transferring phosphorus-containing groups RNA binding binding nucleic acid binding	symbiont-mediated suppression of host transcription symbiont-mediated perturbation of host cellular process biological process involved in interspecies interaction between organisms symbiont-mediated suppression of host mRNA transcription via inhibition of RNA polymerase II activity symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression symbiont-mediated perturbation of host transcription modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction RNA metabolic process viral life cycle primary metabolic process nucleobase-containing compound biosynthetic process symbiont-mediated suppression of host transcription symbiont-mediated perturbation of host cellular process biological process involved in interspecies interaction between organisms symbiont-mediated suppression of host mRNA transcription via inhibition of RNA polymerase II activity symbiont-mediated perturbation of host process symbiont-mediated perturbation of host gene expression symbiont-mediated perturbation of host transcription modulation of process of another organism biological process involved in interaction with host biological process involved in symbiotic interaction RNA metabolic process viral life cycle primary metabolic process nucleobase-containing compound biosynthetic process macromolecule biosynthetic process nucleic acid metabolic process RNA biosynthetic process nucleobase-containing compound metabolic process nucleic acid biosynthetic process viral genome replication biosynthetic process viral RNA genome replication viral process metabolic process cellular process macromolecule metabolic process viral gene expression cap snatching negative stranded viral RNA transcription viral transcription RNA-templated viral transcription symbiont-mediated suppression of host gene expression 7-methylguanosine mRNA capping 7-methylguanosine RNA capping RNA capping gene expression mRNA processing mRNA metabolic process RNA 5'-end processing RNA processing DNA-templated transcription	host intracellular membrane-bounded organelle host cellular component host intracellular part other organism part host cell mitochondrion host cell cytoplasm part host intracellular organelle cellular anatomical structure host cell cytoplasm host cell part host intracellular region host cell nucleus virion component

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR001591	Influenza RNA-dependent RNA polymerase subunit PB2	Family
A	IPR049106	Influenza RNA polymerase PB2, N-terminal region	Domain
A	IPR049115	Influenza RNA polymerase PB2, C-terminal domain	Domain
A	IPR049110	Influenza RNA polymerase PB2, second domain	Domain
A	IPR049114	Influenza RNA polymerase PB2, sixth domain	Domain
A	IPR049113	Polymerase basic protein 2, helical domain	Domain
A	IPR049111	Influenza RNA polymerase PB2, middle domain	Domain
A	IPR048298	Influenza RNA polymerase PB2, CAP binding domain	Domain
A	IPR037258	PB2, C-terminal	Homologous Superfamily

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.