FB2026_03 , released September 17, 2026

CV Term Report

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General Information

Term

ubiquitin-ubiquitin ligase activity

ID (Ontology)

GO:0034450 (Gene Ontology)

Definition

Isoenergetic transfer of ubiquitin from one protein to an existing ubiquitin chain via the reaction X-ubiquitin + Y-ubiquitin = Y-ubiquitin-ubiquitin + X, where both the X-ubiquitin and Y-ubiquitin-ubiquitin linkages are thioester bonds between the C-terminal glycine of ubiquitin and a sulfhydryl side group of a cysteine residue.[ PubMed:10089879 PubMed:17190603 ]

Also Known As

"E4"

Comment

Links to External Ontologies

QuickGO data AmiGO data

Annotations

Records annotated with this term OR any of its CHILD TERMS

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Results list data from multiple species. Choose a record type above to open its HitList.

Direct annotations: records annotated with this exact term (child terms are NOT included)

Data Class	Field	Direct annotations
Genes (FBgn)	GO_MOLECULAR_FUNCTION

Full annotation statements including this term (annotations to child terms are NOT included), and relevant FlyBase records

Full annotation statements	Relevant FlyBase reports
Full annotation statements	Genes
ubiquitin-ubiquitin ligase activity (all annotations which use CV term, excluding "NOT" statements)
enables \| ubiquitin-ubiquitin ligase activity

Spanning Tree (Parents/Children)

ubiquitin-protein transferase activity__
ubiquitin-like protein ligase activity__|
                                        ubiquitin protein ligase activity
                                         |__ubiquitin-ubiquitin ligase activity  5 rec.

Spanning Tree View Settings
Parents/Children View Depth	Show hierarchy levels: for parents, for children
Relationships
Is a	ubiquitin protein ligase activity
Part of
Synonyms & Secondary IDs
Synonyms
	"E4" EXACT
Secondary IDs

External Crossreferences & Linkouts
	Reactome:R-HSA-937050 "Pellino ubiquitinates hp-IRAK1" Reactome:R-HSA-975122 "Pellino ubiquitinates hp-IRAK1 upon TLR7/8 or 9 activation<br>"