Zinc fingers of the paxillin LIM3 domain show increased structural flexibility and are highly conserved across species.

<p>(<b>A</b>) Heteronuclear <sup>15</sup>N{<sup>1</sup>H} NOE. The intensity ratio between spectra with and without <sup>1</sup>H saturation is displayed vs. residue number. Values of 0.8 indicate rigid parts of the structure. Values smaller than 0.8 indicate increasing flexibility on the ps-to-ns timescale. The data underlying this panel can be found in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.3002757#pbio.3002757.s006" target="_blank">S1 Data</a>. On top of the heteronuclear NOE plot, the domain and secondary structure arrangement of the paxillin construct used in this study is depicted. α-Helices are shown in light blue. β-Sheets as magenta arrows. The secondary structure elements depicted here were identified with Pymol’s dss command and correspond to the cartoon representation of the 3D structural ensemble shown in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.3002757#pbio.3002757.g002" target="_blank">Fig 2</a>. The linker connecting the LIM2 with the LIM3 domain is shown in green. Regions harboring flexible loops are shown in blue and grey, respectively. (<b>B</b>) Sequence alignment of paxillin LIM3 domain across different species: Alignment was performed using the structural alignment tool from T-Coffee and coloured using the BoxShade tool at ExPASy. Identical residues are shaded in black; highly similar residues are shaded gray. In addition, an alignment is shown of paxillin’s LIM2 and LIM3 domains. The region harboring a flexible loop, which is crucial for binding of the LIM3 domain to β-integrin, is indicated by a blue line.</p> <p>(PDF)</p>