Fig. 3: hOCCM complexes.
From: MCM double hexamer loading visualized with human proteins
a, Nuclease footprinting assay performed with truncated proteins and ATPγS. Proteins were omitted as indicated. b, Three views of the hOCCM structure. The WH domains of CDT1 (white) interdigitate between the N-terminal A domain of MCM6 and MCM4. c, Yeast Cdt1 (red) and human CDT1 (black) establish the same interactions with the MCM complex in OCCM. d, The MCM2–MCM5 gate is notched but topologically closed by an MCM5 α-helix packing against the MCM2 ATPase. e, Three views of the hOC1M structure. f, Footprinting assay of MCM loading reactions (truncated proteins, no ORC6, ATP) in the presence or absence of CDC6(∆N) using assay buffers containing the indicated sodium acetate (NaOAc) concentrations. g, Salt stability of double hexamer generated in the absence of CDC6 and ORC6 (truncated proteins, ATP). MCM was loaded at 60 mM sodium acetate for 30 min, incubated in buffers containing the indicated salt concentrations for 15 min, then diluted to low salt and treated with benzonase. h, Negative-stain 2D average of hDH loaded in the absence of CDC6 and ORC6 (truncated proteins, 60 mM NaOAc, ATP). i, Footprinting assay with a reaction timecourse in ATPγS (truncated proteins, no ORC6). j, Cryo-EM 2D average of a double OCCM. k, Nuclease footprinting assay with human and yeast MCM loading reactions using either ATP or ATPγS. The experiment was performed at 30 °C.
