Schematic representation of the evolutionary conservation of SR units.

<p>(A) Nesprin-1. (C) Nesprin-2. Each SR unit is coloured according the percentage of conserved residues based on the alignments of vertebrate nesprin-1 and of nesprin-2, separately. The yellow star represents the invariant motif in the unstructured region. Arrows indicate N-termini of short isoforms. (B and D) Number of conservation pbs in each SR unit. Contiguous SR units with >5 pbs are coloured red for nesprin-1 (B) and for nesprin-2 (D).</p

RMSF of the single and double SR units.

<p>(A) RMSF of single units (black and blue lines) and replica simulations performed on the double SR unit (red and green lines) of ^NES1SR70-71. (B) RMSF of single units (black and blue lines) and the replica simulations performed on the double SR unit ^NES2SR52-53. (C) Comparison of the RMSF of the following double SR units: 1S35 (black line), ^NES1SR70-71 replicas (red and green lines) and ^NES2SR52-53 replicas (blue and yellow lines).</p

Ribbon representation of ^NES1SR70-71 (A-B) and ^NES2SR52-53 (C-D).

<p>Close up of the interaction between Phe8113 (magenta spheres) and Gln8169 (cyan spheres) in ^NES1SR70-71 (B) and between Phe6244 Phe8113 (magenta spheres) and Gln8169 (cyan spheres) in ^NES2SR52-53 (D).</p

Consensus sequence for the Pfam SR seed (A) and non-canonical nesprins SRs (B).

<p>The frequency values for the conserved Trp (red) and the Leu (green) are indicated.</p

Summary of the results of the spectroscopic characterisation of the SRs.

<p>In case of multiple thermal unfolding events the temperature of the highest transition is listed in the table.</p

Flowchart for the nesprins SR analysis.

<p>Flowchart for the nesprins SR analysis.</p

Ribbon representation of chicken brain α-spectrin crystal structures.

<p>Representation of (A) single unit SR15 and (B) the three contiguous units SR15-17 of the chicken brain α-spectrin (pdb code1U4Q).</p

Schematic representation of nesprin-1α (A) and nesprin-2β (D); the SR units are coloured with the same colour code as in <b>Figure 5</b><b>.</b>

<p>Panels B-E represent the electrostatic potential surfaces (face 1 and face 2) of ^NES1SR69-71 (B), ^NES1SR72-74 (C), ^NES2SR51-53 (E) and ^NES2SR54-56 (F). Blue – positive potential; red – negative potential. Residues at the centre of a conserved cluster are highlighted with orange dots.</p

Percentage secondary structure of each SR model.

<p>(A) Nesprin-1 SR models. (B) Nesprin-2 SR models. Green lines represent the average percentage secondary structure of the templates. SR units are coloured according Simpson and Roberts <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063633#pone.0063633-Simpson1" target="_blank">[19]</a>: red, SR confidently predicted in two or three paralogues; orange, SR confidently predicted in one paralogue; yellow, region with conserved SR-like secondary structure; pink, confidently predicted SR of atypical length. (C) PsoSA Z-score of the SRs modelled for nesprin-1 (red cross) and for nesprin-2 (green cross) SRs. (D) Zscore distributions of the templates (blue) for the three-helix bundle structure (orange) and for nesperin-1 (red) and nesprin-2 (green).</p

Template structures containing spectrin repeats (SR).

<p>Template structures containing spectrin repeats (SR).</p