Middle phospholipase D-like domain of the transcriptional regulator TrmB and similar proteins
Middle phospholipase D (PLD)-like domain of the transcriptional regulator TrmB and similar proteins. TrmB acts as a bifunctional sugar-sensing transcriptional regulator which controls two operons encoding maltose/trehalose and maltodextrin ABC transporters of Pyrococcus fruiosus. It functions as a dimer. Full length TrmB includes an N-terminal DNA-binding domain, a C-terminal sugar-binding domain and middle region that has been named as a PLD-like domain. The middle domain displays homology to PLD enzymes, which contain one or two HKD motifs (H-x-K-x(4)-D, where x represents any amino acid residue) per chain. The HKD motif characterizes the PLD superfamily. Due to the lack of key residues related to PLD activity in the PLD-like domain, members of this subfamily are unlikely to carry PLD activity.
Feature 1:sugar binding site [chemical binding site]
Evidence:
Comment:The sugar binding site is located near the interface of the middle PLDc-like domain and the C-terminal sugar binding domain. Most residues involved in sugar binding are located at the C-terminal domain.
Structure:2F5T_X; Thermococcus litoralis Trmb binds maltose; contacts at 4A.
Jiyao W et al.(2023). "The conserved domain database in 2023.",