Putative 2,3,4,5-tetrahydropyridine-2,6-dicarboxylate (THDP) N-succinyltransferase (THP succinyltransferase), C-terminal left-handed parallel alpha-helix (LbH) domain: This group is composed of mostly uncharacterized proteins containing an N-terminal domain of unknown function and a C-terminal LbH domain with similarity to THP succinyltransferase LbH. THP succinyltransferase catalyzes the conversion of tetrahydrodipicolinate and succinyl-CoA to N-succinyltetrahydrodipicolinate and CoA. It is the committed step in the succinylase pathway by which bacteria synthesize L-lysine and meso-diaminopimelate, a component of peptidoglycan. The enzyme is trimeric and displays the left-handed parallel alpha-helix (LbH) structural motif encoded by the hexapeptide repeat motif.
Comment:Based on the trimer structures of some members of the superfamily including E. coli Maltose O-acetyltransferase, Chlamydia Trachomatis Lpxd, and E. coli serine acetyltransferase.
Comment:Most characterized members of the LbH superfamily form trimeric structures in their active form. However, there are a few members that form different quaternary structures such as Glucose-1-phosphate adenylyltransferase which forms a tetramer. Hence, not all members may form trimers.
Jiyao W et al.(2023). "The conserved domain database in 2023.",