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Volume 6, Issue 5, Pages 1195-1205 (November 2000)
Crystal Structure of Yeast Esa1 Suggests a Unified Mechanism for Catalysis and Substrate Binding by Histone Acetyltransferases Yuan Yan, Nickolai A. Barlev, Randall H. Haley, Shelley L. Berger, Ronen Marmorstein Molecular Cell Volume 6, Issue 5, Pages (November 2000) DOI: /S (00)
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Figure 1 Characterization of the yEsa1 HAT Domain
(A) Deletion analysis of yESA1. Conserved domains within yEsa1 are indicated on the top. The HAT activity is indicated as +/−. (B) HAT and complementation analysis of GST-Esa1 deletion mutants. HAT activity is indicated relative to wild-type Esa1, and cell growth complementation activity is indicated as +/−. All HAT assays were done in triplicate with less than a 2% standard deviation. (C) HAT activity of yEsa1(160–435). Velocity vs. [histone peptide] is plotted to obtain the substrate specificity constant, kcat/KM (from the slope), for the histone H3p19 (filled squares) and histone H4p19 (filled circles) substrates. Molecular Cell 2000 6, DOI: ( /S (00) )
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Figure 2 Sequence Alignment of the HAT Domain of the MYST Family of Histone Acetyltransferases Dark shading represents conserved residues, while light shading represents chemically similar residues. Secondary structure of Esa1 is indicated above the aligned sequences. Buried residues are indicated as solid balls, and residues involved in CoA interaction are indicated with open triangles. The conserved core domain of the GNAT family of HATs is indicated with a bold line below the corresponding sequences. Molecular Cell 2000 6, DOI: ( /S (00) )
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Figure 3 Overall Structure of Esa1 and Other Histone Acetyltransferases (A) Structure of the Esa1/CoA complex. The central core domain is colored in blue, the N-terminal subdomain is colored in aqua, and the C-terminal subdomain is colored in green. Coenzyme-A is shown as a stick figure in red. (B) Topology diagram of Esa1. (C) Structure of the Tetrahymena Gcn5/CoA/histone H3 peptide complex. The 11 amino acid histone H3 peptide is indicated in pink. (D) Structure of the yeast Hat1/Ac-CoA complex. Molecular Cell 2000 6, DOI: ( /S (00) )
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Figure 4 The Esa1 Catalytic Site
(A) Schematic superposition of the core domains of Esa1 (blue), P/CAF (red), and Hat1 (green) highlighting the corresponding putative catalytic bases, and their associated cofactors, as stick figures. (B) Electrostatic surface of Esa1. White, red, and blue represent electrostatically neutral, electronegative, and electropositive areas, respectively. Molecular Cell 2000 6, DOI: ( /S (00) )
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Figure 5 Phenotypes of the Esa1 (E338Q) Mutant
(A) HAT activity of wild-type and E338Q mutant of Esa1 is greatly reduced by the substitution E338Q. Full-length (left) or HAT domain (residues 160–435) (right) wild-type Esa1 or Esa1(E338Q) were tested for HAT activity. Equivalent amounts of each protein were determined, and then either 1× or 5× this amount was assayed for HAT activity. Full-length Gcn5 (left) or PCAF HAT domain (residues 493–658) (right) was used as a positive control. (B) Growth of yeast is reduced by overexpression of Esa1(E338Q). Either vector alone, wild-type, or mutant Esa1 was expressed at a high level using a galactose-inducible promoter in a strain bearing endogenous wild-type Esa1. Cells were streaked onto media containing glucose (upper) or galactose (lower). (C) Quantification of the effect on yeast growth of overexpression of Esa1(E338Q). Cells containing vector alone, wild-type, or mutant Esa1 (as in [B]) were grown in liquid culture containing galactose for the indicated times and sampled for cell density using optical density at A600. The values were plotted (upper) and used to calculate doubling time during logarithmic growth of the ESA1(WT) culture (lower). (D) Cells containing ESA1(E338Q) exhibit G2/M arrest. Cells were sampled at 34 hr of growth in liquid culture containing galactose (as in [B]) and examined by microscopy. Cells containing ESA1(E338Q) were uniformly (>95%) large budded, while cells containing ESA1(WT) contained cells at all stages of the cell cycle. Molecular Cell 2000 6, DOI: ( /S (00) )
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Figure 6 Putative Substrate and Cofactor Binding Sites for Esa1 and the MYST Proteins (A) Conservation of residues within the MYST family is mapped into a schematic of the Esa1 structure. Only residues that are conserved in at least five of the six MYST members (Figure 2) are shown. Residues that are buried and play a role in protein folding are indicated as pink balls, side chains that interact with CoA (brown) are indicated as green side chains, and other surface exposed conserved side chains are indicated as red side chains. (B) Detailed view of Esa1 interactions with CoA. Only protein regions and side chains residues that mediate direct hydrogen bonds or van der Waals interactions with CoA (red) are indicated. Esa1 color coding is as indicated in the legend to Figure 3A, and a bound water molecule is shown in yellow. (C) Conservation of residues within the MYST family is mapped on the surface of Esa1. Only residues that are conserved in at least five of six MYST members (Figure 2) are shown in yellow coloring. (D) Same as (C) except viewed from the back. (E) Schematic superposition of the putative substrate binding sites of Esa1 (blue, with CoA in red) with the HAT proteins, P/CAF (pink), and Hat1 (green) are schematized. Only the core domain and CoA for Esa1 is shown for clarity. (F) Schematic superposition of the putative substrate binding sites of Esa1 (blue) with N-acetyltransferases that do not target histone substrates; Serotonin N-acetyltransferase (AANAT, green), Aminoglycoside 3-N-acetyltransferase (SmAAT, pink), and Aminoglycoside 6′-N-acetyltransferase (AAC(6′), yellow). Molecular Cell 2000 6, DOI: ( /S (00) )
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