Supplementary Figure 4: SYCP1 N-terminal self-assembly requires both αN-end and αN-tetramer sequences.
From: Structural basis of meiotic chromosome synapsis through SYCP1 self-assembly
(a) Far UV CD spectra and (b) CD thermal denaturation of SYCP1 αN (101-362) (black) and Ntail~αN (1-362) (grey). Helical content was estimated (as indicated) through deconvolution of spectra with data fitted at normalised rmsd values of 0.007 and 0.012 respectively. Thermal denaturation was recorded as % unfolded based on the helical signal at 222 nm; melting temperatures were estimated at 41 °C for both αN and Ntail~αN. (c) Far UV CD spectra of SYCP1 αN-end (101-206) (black), αN-end truncated (101-175) (grey) and Ntail~αN-end (1-175) (wide dashes). Helical content was estimated (as indicated) through deconvolution of spectra with data fitted at normalised rmsd values of 0.005, 0.010 and 0.021 respectively. (d) CD thermal denaturation of SYCP1 αN-end (101–206) (black) and αN-end truncated (101-175) (grey). Thermal denaturation was recorded as % unfolded based on the helical signal at 222 nm; melting temperatures were estimated at 24 °C and 23 °C for αN-end and αN-end truncated respectively. (e) SEC-MALS analysis revealing that SYCP1 αN and Ntail~αN undergo assembly in solution into large molecular weight species. SYCP1 αN forms species of 3-25 MDa; whilst SYCP1 Ntail~αN forms similar assemblies of 2-12 MDa, it is also present in smaller species of 0.15-1 MDa.
