Left-handed parallel beta-Helix (LbetaH or LbH) domain: The alignment contains 5 turns, each containing three imperfect tandem repeats of a hexapeptide repeat motif (X-[STAV]-X-[LIV]-[GAED]-X). Proteins containing hexapeptide repeats are often enzymes showing acyltransferase activity, however, some subfamilies in this hierarchy also show activities related to ion transport or translation initiation. Many are trimeric in their active forms.
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.
Structure:1OCX; Interface between monomers in Escherichia coli Maltose-O-Acetyltransferase trimer; defined at 3.5A contacts. - View structure with Cn3D
Jiyao W et al.(2023). "The conserved domain database in 2023.",