2XV5

Human lamin A coil 2B fragment

Summary for 2XV5

• Entry DOI: 10.2210/pdb2xv5/pdb
• Related: 1IFR 1IVT 1X8Y
• Descriptor: LAMIN-A/C (2 entities in total)
• Functional Keywords: structural protein, intermediate filaments, nuclear membrane; left-handed coiled coil, right-handed coiled coil
• Biological source: HOMO SAPIENS (HUMAN)
• Total number of polymer chains: 2
• Total formula weight: 17898.96

Authors

Kapinos, L.E.,Burkhard, P.,Aebi, U.,Herrmann, H.,Strelkov, S.V. (deposition date: 2010-10-22, release date: 2011-03-09, Last modification date: 2019-03-06)

Primary citation

Kapinos, L.E.,Burkhard, P.,Herrmann, H.,Aebi, U.,Strelkov, S.V.
Simultaneous Formation of Right- and Left-Handed Anti-Parallel Coiled-Coil Interfaces by a Coil2 Fragment of Human Lamin A.
J.Mol.Biol., 408:135-, 2011

PubMed Abstract: The elementary building block of all intermediate filaments (IFs) is a dimer featuring a central α-helical rod domain flanked by the N- and C-terminal end domains. In nuclear IF proteins (lamins), the rod domain consists of two coiled-coil segments, coil1 and coil2, that are connected by a short non-helical linker. Coil1 and the C-terminal part of coil2 contain the two highly conserved IF consensus motifs involved in the longitudinal assembly of dimers. The previously solved crystal structure of a lamin A fragment (residues 305-387) corresponding to the second half of coil2 has yielded a parallel left-handed coiled coil. Here, we present the crystal structure and solution properties of another human lamin A fragment (residues 328-398), which is largely overlapping with fragment 305-387 but harbors a short segment of the tail domain. Unexpectedly, no parallel coiled coil forms within the crystal. Instead, the α-helices are arranged such that two anti-parallel coiled-coil interfaces are formed. The most significant interface has a right-handed geometry, which is accounted for by a characteristic 15-residue repeat pattern that overlays with the canonical heptad repeat pattern. The second interface is a left-handed anti-parallel coiled coil based on the predicted heptad repeat pattern. In solution, the fragment reveals only a weak dimerization propensity. We speculate that the C-terminus of coil2 might unzip, thereby allowing for a right-handed coiled-coil interface to form between two laterally aligned dimers. Such an interface might co-exist with a heterotetrameric left-handed coiled-coil assembly, which is expected to be responsible for the longitudinal A(CN) contact.

PubMed: 21354179
DOI: 10.1016/J.JMB.2011.02.037

Experimental method

X-RAY DIFFRACTION (2.4 Å)