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Figure 1
(a) Structure of the lactoglobulin homodimer with the mutation sites L39A, I56F and M107F (or M107W) marked by red spheres; cyan spheres mark the N-­terminal L1A/I2S substitutions. The dimer subunit A (chain A) is colored light green, while subunit B (chain B) is in dark green. (b) Topology diagram of the BLG homodimer with mutation sites marked as in (a) and with labels for β-strands (arrows) A–I and for the following strand-connecting loops: AB, CD, EF and GH. α-Helices are marked as rectangles without labels. In (a) and (b) the hydrogen bonds responsible for dimerization are marked by red dotted lines. (c) The green shapes represent BLG dimer subunits (light green, chain A; dark green, chain B). In FAF, FAF–DSM, FAW–DSM#1 and FAW–DSM#2 the asymmetric unit contains the BLG dimer (chain A and chain B), while in FAW and FAW–DSM#3 the dimer is generated by a crystallographic twofold axis (chain A and symmetry-related chain A′). The colored shapes represent DSM molecules: DSM I (pink), DSM II (cyan), DSM III (yellow), DSM IV (orange) and the single DSM in FAW–DSM#3 (blue). Ligands with fractional occupancy are marked with white stripes. Crystals of FAW–DSM#2 and FAW–DSM#3 grew simultaneously in the same crystallization drop (black frame). Space-group symbols are given at the bottom of (c).

IUCrJ
Volume 9| Part 3| May 2022| Pages 386-398
ISSN: 2052-2525
https://doi.org/10.1107/S2052252522004183