Amino acid sequence of Pp-IsdC and heme binding analysis.

<p><b><i>A</i></b>- Amino acid sequence of full-length Pp-IsdC. The signal cleavage site is indicated by the arrowhead, and the NEAT domain (Pp-IsdC_N) is highlighted in grey. The 3₁₀-helix is boxed in black, and the two tyrosine residues within the heme-binding signature sequence are bolded. <b><i>B</i></b>- Spectral analysis of purified Pp-IsdC shows the presence of a Soret band at 404 nm, indicating that the protein can bind heme. The red spectra, magnified ×5, indicates Q bands at 500 and 630 nm, demonstrating that the heme bound by Pp-IsdC is oxidized (Fe³⁺) and is in a high-spin coordination <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0104794#pone.0104794-Berry1" target="_blank">[67]</a>. <b><i>Inset:</i></b> SDS-PAGE of purified Pp-IsdC_N at 14 kDa.