Assembly of a nuclear lamin coil 2 fragment

Nuclear structure and function are governed by lamins, which are intermediate filaments mostly consisting of α-helices. Different lamin assembly models have been proposed based on low resolution or fragmented structures. However, their assembly mechanisms at the molecular level are poorly understood. The structure shows the anti-parallel arrangement of two coiled-coil dimers, which is important for the assembly process. We further discovered a new interaction of a coil 2 by using chemical cross-linking and mass analysis, of which the results were deposited in the PRIDE identifier PXD013144. Here we showed that a cysteine-substituted coil 2 R388C segment (286-400 amino acid residues of lamin) was dimerized by the chemical crosslinking. Our findings also provide a molecular basis for the assembly mechanisms of other intermediate filaments.