Isopeptide bonds of BP-2b.

<p>Domains D2 and D3 are colored as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125875#pone.0125875.g001" target="_blank">Fig 1</a> in blue and orange, respectively. Isopeptide bonds between Asn330 and Lys 187 for D2, and between Asn462 and Lys358 in D3 are shown with blue and orange sticks, and 1σ 2<i>F</i>o-<i>F</i>c electron density map around this region is shown as blue mesh (carve = 1.1). The magenta colored regions in (A) and (B) show the location of hydrophobic residues surrounding the isopeptide bonds. Hydrogen-bonds between the isopeptide bonds and the nearby Asp (225, D2) and Glu (423, D3) are shown with black dashed lines.