Major ampullate spidroin 1, spider silk protein 1, N-term
Spidroin is produced by a number of arachnids. Spidrions are made up of repetitive segments flanked by conserved non-repetitive domains, and this domain is the conserved non-repetitive region. Aggregation to form the rigid silk occurs due to association at the repetitive regions, and the N-terminal domain is necessary to prevent premature aggregation during storage before extrusion. This N_terminal region inhibits precocious aggregation and then accelerates and directs self-assembly as the pH is lowered along the extrusion duct.