Figure 6

The binding mode of BTN and BSO. (a) BTN (thick sticks) and the amino acids within 4 Å of BTN in the BBP-A – BTN and AVD [PDB: 2AVI] structures are shown. The carbon atoms of residues from subunit 1 of the BBP-A and AVD structures are coloured light grey and blue, respectively. The carbon atoms of Trp111 (Trp110) from subunit 2 of BBP-A (AVD) are coloured green (cyan). The amino acids of BBP-A (AVD) are numbered. The labels of the non-conserved residues are indicated with a yellow background. (b) BTN and BSO (thick sticks), and the amino acids within 4 Å of the ligands in the BBP-A – BTN and BBP-A – BSO structures are shown. The carbon atoms of residues from subunits 1 of the BBP-A – BTN and BBP-A – BSO structures are coloured light grey and light red, respectively. The carbon atoms of Trp111 from subunit 2 of the BBP-A – BTN and BBP-A – BSO structure are coloured green and dark red, respectively. The amino acids are numbered. Glu102, whose side chain has a different conformation in the BBP-A – BTN and BBP-A – BSO structures, is labelled with a yellow background.