The l-leucine-responsive regulatory protein (Lrp/AsnC) family is a family of similar bacterial transcription regulatory proteins. The family is named after two E. coli proteins involved in regulating amino acid metabolism. This entry corresponds to the usually C-terminal regulatory ligand binding domain. Structurally this domain has a dimeric alpha/beta barrel fold [2]. This domain binds almost exclusively amino acids but also 4-hydroxyphenylpyruvate and kynurenine (Matilla et. al., FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043).

1: The eubacterial transcriptional activator Lrp is present in the archaeon Pyrococcus furiosus. Kyrpides NC, Ouzounis CA; Trends Biochem Sci 1995;20:140-141. PMID:7770911

2: The structure and transcriptional analysis of a global regulator from Neisseria meningitidis. Ren J, Sainsbury S, Combs SE, Capper RG, Jordan PW, Berrow NS, Stammers DK, Saunders NJ, Owens RJ; J Biol Chem. 2007;282:14655-14664. PMID:17374605