Fig. 2: TEX12 undergoes conformational change from dimer to tetramer upon Ctip mutation.
From: Coiled-coil structure of meiosis protein TEX12 and conformational regulation by its C-terminal tip
a SDS-PAGE of purified TEX12 core (amino acids 49–123; herein referred to as TEX12) proteins containing wild-type (WT, blue), ΔCtip (deletion of amino-acids 114–123, yellow), LFIL (L110E F114E I117E L121E, green) and FFV (F102A F109E V116A, red) sequences. b, c Circular dichroism (CD) analysis. b Far UV circular dichroism (CD) spectra recorded between 260 and 185 nm in mean residue ellipticity, MRE ([θ]) (x1000 deg.cm2.dmol−1.residue−1). Data were deconvoluted using the CDSSTR algorithm, with helical content indicated. c CD thermal denaturation recording the CD helical signature at 222 nm between 5 and 95 °C, as % unfolded. Melting temperatures were determined from the second derivatives of the curves. d–f SEC-MALS analysis in which differential refractive index (dRI; solid lines) is shown with fitted molecular weights (Mw; dashed lines) plotted across elution peaks. d TEX12 wild-type (WT) is a 17 kDa dimer, whereas the FFV mutant is a 33 kDa tetramer (theoretical—18 and 36 kDa); samples were analysed at >10 mg/ml (red and blue) and at 1 mg/ml (grey). e, f SEC-MALS analysis of TEX12 (e) ΔCtip and (f) LFIL mutants at concentrations between 1 and 12 mg/ml (as shown), indicating concentration-dependent dissociation of species intermediate between the theoretical masses of dimers and tetramers (ΔCtip—16 and 32 kDa; LFIL—18 and 36 kDa). g TEX12 is a dimer that undergoes conformational change into a tetramer by FFV mutation, and forms a mixture of less stable species, in equilibrium between dimer and tetramer, upon ΔCtip and LFIL mutations.
