Catalyzes the phosphorylation of the beta-carboxyl group of aspartic acid with ATP to yield 4-phospho-L-aspartate, which is involved in the branched biosynthetic pathway leading to the biosynthesis of amino acids threonine, isoleucine and methionine. ATP + L-aspartate = 4-phospho-L-aspartate + ADP Lysine-sensitive. Regulated by degradation in response to starvation of cells for various nutrients. Ammonium starvation induced the fastest aspartokinase II decline, followed by amino acid starvation and glucose limitation. kcat is 952 min(-1). Amino-acid biosynthesis; L-lysine biosynthesis via DAP pathway; (S)-tetrahydrodipicolinate from L-aspartate: step 1/4. Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-homoserine from L-aspartate: step 1/3. Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine from L-aspartate: step 1/5. Tetramer consisting of 2 isoforms Alpha (catalytic and regulation) and of a homodimer of 2 isoforms Beta (regulation). Belongs to the aspartokinase family.