Difference between revisions of "Part:BBa K3848009"

Revision as of 19:19, 11 October 2023

LLDR LldR (CGL2915) from Corynebacterium glutamicum is a transcription factor belonging to the GntR family, which is typically involved in the regulation of oxidized substrates associated with amino acid metabolism. Sensitivity of the lldR promoter can be regulated by the expression of lldP which increases the import of lactate inside the cell.

KCL 2023 -

The previous information about the species where this sequence was derived from was incorrect. This part was described as being a protein from Corynebacterium glutamicum, but BLAST analysis shows that the nucleotide sequence matches E. coli (99% similarity).

LldR from Escherichia coli (E. coli) is a lactate-responsive transcription factor belonging to the GntR family. LldR governs the expression of the lldPRD operon in various bacterial species including E. coli and Corynebacterium glutamicum (BBa_K4584000).

LldR represses the expression of the lldPRD operon by binding to the O1 and O2 operator regions, in E. coli. In presence of L-lactate, the affinity of LldR to the operator regions changes, resulting in expression of lactate dehydrogenase and lactate permease.

Members of the GntR family are characterised by a highly conserved winged helix-turn-helix motif (wHTH) in their N-terminus domain (NTD) responsible for DNA binding. This helix-turn-helix motif is comprised of a tri-helical core, with helices 2 and 3 interacting specifically with the major groove of the DNA. Following the helical core, two beta strands are linked through a small loop, referred to as the "wing" motif. However, these transcription factors display variations in their C-terminal effector-binding and oligomerization domains. In the case of LldR, the C-terminal effector binding domain is responsible for binding to L-lactate.

Sequence and Features