piccolo histone acetyltransferase complex

GO:0032777 · Other · Multiprotein complex · Proposed

A heterotrimeric H4/H2A histone acetyltransferase complex with a substrate preference of chromatin over free histones. It contains a subset of the proteins found in the larger NuA4 histone acetyltransferase complex; for example, the S. cerevisiae complex contains Esa1p, Yng2p, and Epl1p. [GO:0032777]

Synonyms: Piccolo NuA4 complex; picNuA4 complex

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

Components

Component	Type	Part of / acts on	Grounding	Genes	Essential	Role
Esa1 piccolo NuA4 catalytic subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	ESA1	UNKNOWN	Catalytic MYST-family histone acetyltransferase constituent of the budding-yeast piccolo NuA4 complex. `GO:0032777` GO:0032777 defines the S. cerevisiae piccolo complex as containing Esa1p. `DOI:10.1101/gad.1056603` Boudreault et al. 2003 identified Esa1 as a Piccolo NuA4 subunit. `DOI:10.1128/MCB.25.13.5535-5542.2005` Selleck et al. 2005 reconstituted Piccolo with Esa1 and minimal Epl1/Yng2 segments.
Epl1 piccolo NuA4 bridging subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	EPL1	UNKNOWN	Piccolo NuA4 constituent whose N-terminal region links Esa1 and Yng2 in the budding-yeast heterotrimer. `GO:0032777` GO:0032777 defines the S. cerevisiae piccolo complex as containing Epl1p. `DOI:10.1101/gad.1056603` Boudreault et al. 2003 identified Epl1 as a Piccolo NuA4 subunit. `DOI:10.1128/MCB.25.13.5535-5542.2005` Selleck et al. 2005 tested the Epl1 minimal region that supports Piccolo nucleosome activity.
Yng2 piccolo NuA4 subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	YNG2	UNKNOWN	ING-family constituent of the budding-yeast piccolo NuA4 complex. `GO:0032777` GO:0032777 defines the S. cerevisiae piccolo complex as containing Yng2p. `DOI:10.1101/gad.1056603` Boudreault et al. 2003 identified Yng2 as a Piccolo NuA4 subunit. `DOI:10.1128/MCB.25.13.5535-5542.2005` Selleck et al. 2005 tested the Yng2 minimal region that supports Piccolo nucleosome activity.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast is the organism in which GO:0032777 defines the heterotrimeric piccolo complex as containing Esa1p, Yng2p and Epl1p. [GO:0032777]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Boudreault et al. 2003 isolated native and recombinant Piccolo NuA4 from budding yeast as an Esa1/Epl1/Yng2 complex. [DOI:10.1101/gad.1056603]

Functions

histone acetyltransferase activity GO:0004402 — Piccolo NuA4 catalyzes Esa1-dependent histone H4/H2A acetylation with a preference for chromatin substrates.
- GO:0032777 GO:0032777 defines piccolo as a H4/H2A histone acetyltransferase complex.
- GO:0004402 GO:0004402 is the Gene Ontology molecular-function term for histone acetyltransferase activity.
- DOI:10.1101/gad.1056603 Boudreault et al. 2003 reported chromatin-preferring Piccolo NuA4 activity.

Mechanism graphs

Piccolo NuA4 carries yeast histone acetyltransferase activity (FUNCTION)

In Saccharomyces cerevisiae, Esa1p, Epl1p and Yng2p form the piccolo histone acetyltransferase complex.

Subject	Predicate	Object	Evidence
Esa1 piccolo NuA4 catalytic subunit	contributes to	piccolo histone acetyltransferase complex	`GO:0032777` GO:0032777 defines Esa1p as a piccolo constituent. `DOI:10.1101/gad.1056603` Boudreault et al. 2003 identified Esa1 in Piccolo NuA4.
Epl1 piccolo NuA4 bridging subunit	contributes to	piccolo histone acetyltransferase complex	`GO:0032777` GO:0032777 defines Epl1p as a piccolo constituent. `DOI:10.1101/gad.1056603` Boudreault et al. 2003 identified Epl1 in Piccolo NuA4.
Yng2 piccolo NuA4 subunit	contributes to	piccolo histone acetyltransferase complex	`GO:0032777` GO:0032777 defines Yng2p as a piccolo constituent. `DOI:10.1101/gad.1056603` Boudreault et al. 2003 identified Yng2 in Piccolo NuA4.
piccolo histone acetyltransferase complex	supports	histone acetyltransferase activity	`GO:0032777` GO:0032777 defines piccolo as a H4/H2A histone acetyltransferase complex. `DOI:10.1101/gad.1056603` Boudreault et al. 2003 reported Piccolo NuA4 HAT activity.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for the piccolo NuA4 constituents. GO:0032777 defines three budding-yeast proteins as piccolo constituents. Exact source-neutral InterPro, Pfam, NCBIfam or UniProt family boundaries for these piccolo NuA4 subunit classes need narrower curation before these component labels can be grounded.

Evidence

GO:0032777 Gene Ontology cellular-component term for the piccolo histone acetyltransferase complex.
GO:0043189 Gene Ontology cellular-component parent term for H4/H2A histone acetyltransferase complexes.
GO:0004402 Gene Ontology molecular-function term for histone acetyltransferase activity.
PMID:12782659 PubMed identifier for Boudreault et al. 2003, the Piccolo NuA4 Esa1/Epl1/Yng2 paper cited by GO:0032777.
DOI:10.1101/gad.1056603 DOI for Boudreault et al. 2003, 'Yeast enhancer of polycomb defines global Esa1-dependent acetylation of chromatin', verified through NCBI E-utilities.
PMID:15964809 PubMed identifier for Selleck et al. 2005, the Piccolo NuA4 nucleosome substrate paper cited by GO:0032777.
DOI:10.1128/MCB.25.13.5535-5542.2005 DOI for Selleck et al. 2005, 'The Saccharomyces cerevisiae piccolo NuA4 histone acetyltransferase complex requires the enhancer of polycomb A domain and chromodomain to acetylate nucleosomes', verified through NCBI E-utilities.

Curation history

2026-09-27T05:53:41Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-27T05:54:38Z codex · EXPANDED_RECORD — Added H4/H2A parentage, two Piccolo NuA4 synonyms, three budding-yeast constituent rows, budding-yeast scope, histone acetyltransferase activity, GO/PubMed/DOI evidence, a nonmechanistic function graph, and a piccolo NuA4 subunit-grounding TODO.

Source: data/structures/other/piccolo_histone_acetyltransferase_complex.yaml