Structure of YesX. A, overall structure. B, image
in A is turned by 90° around the x axis. C,
superimposition of YesW (blue) and YesX (pink). D, topology
diagram. β-Sheets are shown as blue or green arrows,
and helices are pink cylinders. The calcium ions are shown as orange
balls. E, structural comparison of YesW and YesX in the active site.
Residues are colored blue for YesW and pink for YesX. A
calcium ion is shown as an orange ball. Loop specific for YesX is
colored red and indicated by an arrow. F, comparison in the
surface structure among YesX, YesW/GalA-GalA, and YesW/Rha. The loop specific
for YesX is colored red. Disaccharide is shown by colored elements:
oxygen atom, red; carbon atom, green. The calcium ions are
shown as orange balls, and GalA and Rha molecules are shown by
green and magenta sticks, respectively. G, amino
acid sequence alignment of YesW and YesX (GenPept accession number CAB12524
for YesW and CAB12525 for YesX). Amino acid sequences were aligned using the
ClustalW program. Identical residues are denoted by
asterisks, strongly conserved residues are denoted by
colons, and weakly conserved residues are denoted by
periods. The inserted sequence, which corresponds to the loop
specific for YesX, is shown in red letters.