FB2026_03 , released September 17, 2026

CV Term Report

Help Close All Open All

General Information

Term

ubiquitin activating enzyme activity

ID (Ontology)

GO:0004839 (Gene Ontology)

Definition

Catalysis of the reaction: E1 + ubiquitin + ATP--> E1-ubiquitin + AMP + PPi, where the E1-ubiquitin linkage is a thioester bond between the C-terminal glycine of Ub and a sulfhydryl side group of an E1 cysteine residue. This is the first step in a cascade of reactions in which ubiquitin is ultimately added to a protein substrate.

Comment

Links to External Ontologies

QuickGO data AmiGO data

Annotations

Records annotated with this term OR any of its CHILD TERMS

Choose a record type to view annotations for this term and its child terms. Direct annotations and full annotation statements below also provide HitList buttons.

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	Gene Groups	Genes
ubiquitin activating enzyme activity (all annotations which use CV term, excluding "NOT" statements)
enables \| ubiquitin activating enzyme activity	--

Spanning Tree (Parents/Children)

ligase activity, forming carbon-sulfur bonds__
catalytic activity, acting on a protein_______|
ATP-dependent activity________________________|
                                              ubiquitin-like modifier activating enzyme activity
                                               |__ubiquitin activating enzyme activity  3 rec.

Spanning Tree View Settings
Parents/Children View Depth	Show hierarchy levels: for parents, for children
Relationships
Is a	ubiquitin-like modifier activating enzyme activity
Part of
Synonyms & Secondary IDs
Synonyms
	"E1 ubiquitin-activating enzyme" RELATED[ EC:6 ]
Secondary IDs

External Crossreferences & Linkouts
	EC:6.2.1.45 Reactome:R-HSA-8852132 "Ub-Cys632-UBA1 adenylates ubiquitin in the cytosol" Reactome:R-HSA-8852133 "UBA1 conjugates ubiquitin to UBA1 in the cytosol" Reactome:R-HSA-8852134 "UBA1 adenylates ubiquitin in the cytosol" Reactome:R-HSA-8865050 "Ub-Cys625-UBA6 adenylates ubiquitin in the cytosol" Reactome:R-HSA-8865090 "UBA6 adenylates ubiquitin in the cytosol" Reactome:R-HSA-8865098 "UBA6 conjugates ubiquitin to UBA6 in the cytosol"