The architecture of the apo LAP crystal structure. (a) The asymmetric unit of the crystal structure of apo LAP shown as a cartoon model. Naming conventions follow those of Shi et al. (2011). Nonterminal missing regions are indicated by dashed lines. (b) A schematic of the LTGFβ-1 gene and the residues included in crystallization and model building. (b) A schematic showing the jelly-roll fold. The α3 helix connecting β-strands 2 and 3 is highlighted in yellow.