ORC-associated histone acetylation. (A) Incorporation of 14C-AcCoA into core histones from chicken erythrocytes by ORC-associated histone acetyltransferase. The upper panel shows PhosphorImage of 14C-labeled histones and the lower panel shows Coomassie stained gel. Protein introduced in the assay was 10, 5, 2, and 1.25 μl of the TAP-purified and concentrated product (approximately 100 ml). (B) Quantification of the results in panel A. Disintegrations/decays per min are shown on the Y-axis. (C) Equal volumes of TAP-purified proteins used for the HAT assay from ORC5-TAP (BSY700), ORC5-TAP hat1Δ (BSY701), and untagged control strain (JRY2334) are loaded on a silver stain gel.