Catalyzes the transfer of an acetyl group from acetyl-CoA to tetrahydrodipicolinate. (S)-2,3,4,5-tetrahydrodipicolinate + acetyl-CoA + H2O = CoA + L-2-acetamido-6-oxoheptanedioate Amino-acid biosynthesis; L-lysine biosynthesis via DAP pathway; LL-2,6-diaminopimelate from (S)-tetrahydrodipicolinate (acetylase route): step 1/3. Belongs to the transferase hexapeptide repeat family. DapH subfamily.