Fig. 3: MORC2 acts as a DNA clamp with phosphorylation-dependent ATPase activity.
From: MORC2 is a phosphorylation-dependent DNA compaction machine
a In vitro Fluorescence Polarisation ATPase activity of MORC2 WT, ATPase (1-603) and PD mutant. Individual measurements (n = 3) are shown as points, and the solid line represents the non-linear fit of the data. The indicated kcat values are mean ± standard error of mean (SEM) representative of three experiments. b Surface plasmon resonance analysis of MORC2 WT, ATPase (1-603) and PD mutant with protein concentrations of 4, 8, 16, 33, 63, 125, 250 and 500 nM. Values for KD (equilibrium dissociation constant), ka (association rate constant) and kd (dissociation rate constant) are shown as mean ± SEM, representative of three experiments. c Schematic of competition EMSA with input IRDye800dsDNA (column 1), pre-incubated with no DNA (column 2), 101 bp linear (column 3) and 101 bp circular DNA (column 4) is shown on top. The 100 nM MORC2 WT protein was pre-incubated with no DNA, 200 nM 101 bp linear or 200 nM 101 bp circular DNA for 30 min, followed by 10 min incubation with 50, 100, 200, 400 or 800 nM 90 bp IRDye800-labelled dsDNA. The protein to IRDye800-labelled DNA concentration (nM) in controls (lane 2 in Column 2, Column 3 and 4) is 100:800. The reaction is resolved on 6% PAGE gel. SYBR gold (top) and IRDye800 (bottom) channel images are shown. *indicates background circular DNA bands. The MORC2 protein and linear and circular DNA cartoons were created in BioRender. Tan, W. (2025) https://BioRender.com/xfcicda. d Quantification of the IRDye800-labelled DNA bound to MORC2, calculated as described in Supplementary Fig 10a. The points are shown as mean ± standard deviation (SD) from three independent experiments; number of independent experiments (n) = 3. For Fig. 3a-d, source data are provided as a Source Data file.
