Crystallographic data and refinement statistics of human GUS.

a<p>– numbers in parenthesis correspond to the highest resolution shell of (1.67–1.73 Å for data collection, 1.7–1.74 Å for refinement).</p

Structure of GUS monomer shown in cartoon model.

<p>Jelly roll domain, immunoglobulin constant region domain and TIM barrel domains are shown in yellow, green and red respectively. Residues involved in catalysis are shown in ball and stick model (cyan). Potential glycosylation sites and N-linked oligosaccharide chains are shown in light grey and orange respectively (ball and stick model). The hairpin loop proposed to be involved in lysosomal targeting is shown in pink.</p

List of proteins showing structural similarities with human GUS.

a<p>Number of residues aligned.</p>b<p>Total number of residues.</p>c<p>Root mean square deviations for C^α atoms.</p

Structural comparison of human GUSB with bacterial GUS.

<p>(<b>A</b>). Cartoon model of superimposed human (light red) and bacterial GUS (green). Residues involved in catalysis are shown in ball and stick model for both the human (light red) and bacterial GUS (light green). (<b>B</b>). Superposition of the longer loop of bacterial GUS (light green) involved in binding to the inhibitor (yellow stick) and superimposed side chains of active site residues of human and bacterial GUS. (<b>C</b>). Comparison of lysosomal target loop of human GUS with bacterial GUS. Atomic coordinates of bacterial GUS were taken pdb code 3LPG <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079687#pone.0079687-Wallace1" target="_blank">[51]</a>.</p

Overall structure of human GUS illustrated in cartoon model.

<p>Subunits A, B, D, and E are colored in green, light red, grey and sky blue, respectively. Residues involved in the catalysis are shown in ball and stick model (cyan) on each monomer. N-linked oligosaccharide chains are shown in ball and stick model (orange). The hairpin loop of each monomer is shown in magenta. All structures are drawn using the molecular visualization tool, PyMOL (The PyMOL Molecular Graphics System, Version 1.3, Schrödinger, LLC).</p

Cartoon model of superimposed human GUS and bacterial β-galactosidas.

<p>(<b>A</b>). Roll jelly like domain and (<b>B</b>). TIM barrel domains. Human GUS is shown in light red and bacterial β-galactosidase in sky blue. The side chains of active site residues of human and bacterial GUS are shown in ball and stick. Atomic coordinates of bacterial protein were taken from pdb code 1DP0 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079687#pone.0079687-Juers1" target="_blank">[52]</a>.</p

Multiple sequence alignment of human GUS with mouse and bacterial GUS.

<p>The percent sequence identities are given in parentheses. Completely conserved residues and homologous residues are shaded in dark and light grey, respectively. The secondary structure elements are given on the top of sequences, where α-helices are represented by blue rectangles, β-strands by green arrows. Domains 1, 2 and 3 are indicated by yellow, green and red line respectively, below the sequence. Conserved active site residues are highlighted in green boxes. Potential glycosylation sites are in pink. Glycosylation sites are in magenta boxes. Amino acid sequences of GUS were taken from the Uniprot database with their primary accession number as: human, P08236; mouse P12265; and <i>E. coli</i>, P05804.</p

Representation of N-linked oligosaccharide chain on GUSB.

<p>(<b>A</b>). N-linked oligosaccharide chain at Asn173 and the lysosome targeting loop. Superimposed structure of reported earlier (1BHG, yellow) and the current structure (orange) of human GUS showing different orientation of lysosomal targeting motif. The side chain of Lys197, which is believed to participate in phosphotransferase recognition, is coordinated by the glycan chain at Asn173. <b>B</b>. N-linked oligosaccharide chain at Asn272. Contour electron density map (at the electron level 1.00 for a 2Fo-F) is shown with the modeled glycan chain. <b>C</b>. Stereo view of cartoon diagram showing a comparison of lysosomal target motif of human GUS (light red) with cathepsin D (cyan). The structure was drawn from the atomic coordinates of cathepsin D with pdb code, 1LYA <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079687#pone.0079687-Flores1" target="_blank">[40]</a>.</p