ACF complex

GO:0016590 · Other · Multiprotein complex · Proposed

An ISWI complex that contains an ATPase subunit of the ISWI family (SNF2H in mammals, Isw2 in S. cerevisiae), an ACF1 homolog, and generally no other subunits, though Xenopus is an exception with a third non-conserved subunit. ACF plays roles in regulation of RNA polymerase II transcription and in DNA replication and repair. [GO:0016590]

Synonyms: ATP-utilizing chromatin assembly and remodeling factor complex

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
Isw2 ACF ATPase subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	ISW2		UNKNOWN	ISWI-family ATPase constituent of the budding-yeast two-subunit ACF-like Isw2 chromatin-remodeling complex. `DOI:10.1128/MCB.21.6.2098-2106.2001` Gelbart et al. 2001 purified Isw2p with Itc1p and found that both subunits were required for the ATPase and chromatin-remodeling activities of the Isw2 complex.
Itc1 ACF subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	ITC1		UNKNOWN	WAC-motif constituent paired with Isw2 in the budding-yeast two-subunit ACF-like Isw2 chromatin-remodeling complex. `DOI:10.1128/MCB.21.6.2098-2106.2001` Gelbart et al. 2001 identified YGL133w, named ITC1, as the second subunit of the budding-yeast Isw2 complex.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast is the source organism in which Gelbart et al. biochemically characterized the two-subunit Isw2/Itc1 complex. [DOI:10.1128/MCB.21.6.2098-2106.2001]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Gelbart et al. 2001 purified the two-subunit Isw2 complex from Saccharomyces cerevisiae and identified Itc1p as its second subunit. [DOI:10.1128/MCB.21.6.2098-2106.2001]

Functions

chromatin remodeling GO:0006338 — The ACF-like Isw2/Itc1 complex carries ATP-dependent chromatin remodeling activity in Saccharomyces cerevisiae.
- GO:0006338 GO:0006338 is the Gene Ontology biological-process term for chromatin remodeling.
- GO:0016590 GO:0016590 defines the ACF cellular component as an ISWI complex.
- DOI:10.1128/MCB.21.6.2098-2106.2001 Gelbart et al. 2001 found that Isw2p and Itc1p were both required for chromatin-remodeling activity of the Isw2 complex.

Mechanism graphs

ACF supports yeast chromatin remodeling (FUNCTION)

In Saccharomyces cerevisiae, Isw2 and Itc1 form the two-subunit ACF-like Isw2 chromatin-remodeling complex.

Subject	Predicate	Object	Evidence
Isw2 ACF ATPase subunit	contributes to	ACF complex	`DOI:10.1128/MCB.21.6.2098-2106.2001` Gelbart et al. 2001 purified and reconstituted the budding-yeast Isw2/Itc1 complex.
Itc1 ACF subunit	contributes to	ACF complex	`DOI:10.1128/MCB.21.6.2098-2106.2001` Gelbart et al. 2001 purified and reconstituted the budding-yeast Isw2/Itc1 complex.
ACF complex	enables	chromatin remodeling	`DOI:10.1128/MCB.21.6.2098-2106.2001` Gelbart et al. 2001 found that both Isw2p and Itc1p were required for chromatin-remodeling activity of the complex.

Discussions

CURATION_TODO (OPEN): Curate exact source-neutral InterPro, Pfam, NCBIfam or UniProt family groundings for the ACF Isw2 and Itc1 component classes when terms that denote those classes can be verified. Isw2 and Itc1 occur in both two-subunit ACF-like and four-subunit CHRAC-like complexes, so exact grounding should avoid broad ATPase or WAC-domain terms that do not denote these ACF component roles.

Evidence

GO:0016590 Gene Ontology cellular-component term for the ACF complex.
GO:0031010 Gene Ontology cellular-component parent term for ISWI-type complexes.
GO:0006338 Gene Ontology biological-process term for chromatin remodeling.
PMID:11238944 PubMed identifier for Gelbart et al. 2001, the Molecular and Cellular Biology paper that identified ITC1 as the second subunit of the budding-yeast Isw2 complex.
DOI:10.1128/MCB.21.6.2098-2106.2001 DOI for Gelbart et al. 2001, 'Interactions of Isw2 chromatin remodeling complex with nucleosomal arrays: analyses using recombinant yeast histones and immobilized templates', verified through NCBI E-utilities.
PMID:15024052 PubMed identifier for McConnell et al. 2004, the Molecular and Cellular Biology paper that separated the two-subunit and four-subunit Isw2 complexes.
DOI:10.1128/MCB.24.7.2605-2613.2004 DOI for McConnell et al. 2004, 'Histone fold protein Dls1p is required for Isw2-dependent chromatin remodeling in vivo', verified through NCBI E-utilities.

Curation history

2026-09-27T03:15:26Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-27T03:16:05Z codex · EXPANDED_RECORD — Added ACF exact synonymy, ISWI-type parentage, Isw2 and Itc1 constituent rows, yeast scope, chromatin-remodeling function, GO/PubMed/DOI evidence, a nonmechanistic function graph, and a subunit-grounding TODO.

Source: data/structures/other/acf_complex.yaml