Assembly of the catalytic trimers of aspartate transcarbamoylase from folded monomers.

C, catalytic subunit; R, regulatory subunit; ATCase, aspartate transcarbarnoylase; c, catalytic polypeptide chain; r, regulatory polypeptide chain; GRa, ATCase molecule in terms of its subunit structure composed of two C and three R subunits; cf16, ATCase molecule designated by its constituent six c and six r polypeptide chains; CS, succinylated C subunit; C,,,, catalytic subunit composed of three native chains; C, , , catalytic trimer containing three succinylated chains; C,,,, hybrid catalytic subunit composed of two native and one succinylated chains; C, , , hybrid catalytic subunit containing one native and two succinylated chains; C,, rnonomeric native chain; C,, monomeric succinylated chain; C,,, dimer containing two native chains; SDS, sodium