Figure 2. Topology diagram of DTBSes.
β-strands are shown as arrows pointing toward the C-terminus. Helices are shown as dark rods above the plane of the β-sheet, or as light gray rods below the β-sheet. A black arrowhead marks the N-terminus of the protein, and the C-termini are depicted as black dots. The center panel shows the region common to all four structures: 1BYI (ecDTBS), 2QMO (hpDTBS), 3FGN (mtDTBS) and 3OF5 (ftDTBS). The left panel displays the topological differences between the C-termini of these proteins. The right panel shows the differences in secondary structure of mtDTBS versus the other DTBS structures β-strands 2 and 3. Diagrams were prepared using the protocol of PROMOTIF [51] for secondary structure assignment of apo-forms of enzymes. The annotation of secondary structure elements is consistent with the annotation made previously for ecDTBS [13]