Structural insight into gene transcriptional regulation and effector binding by the Lrp/AsnC family

• Published in: Nucleic acids research Vol. 34; no. 5; pp. 1439 - 1449
• Main Authors: Thaw, P, Sedelnikova, S.E, Muranova, T, Wiese, S, Ayora, S, Alonso, J.C, Brinkman, A.B, Akerboom, A.P, Oost, J. van der, Rafferty, J.B
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-01-2006; Oxford Publishing Limited (England)
• Subjects: agrobacterium-tumefaciens; Amino Acid Sequence; archaeon pyrococcus-furiosus; Asparagine - chemistry; Asparagine - metabolism; Bacillus subtilis; bacillus-subtilis lrpc; Bacterial Proteins - chemistry; Bacterial Proteins - classification; Bacterial Proteins - metabolism; crystal-structure; dna-binding; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - classification; Escherichia coli Proteins - metabolism; escherichia-coli lrp; Gene Expression Regulation, Bacterial; global regulator; Ligands; macromolecular structures; Models, Molecular; Molecular Sequence Data; protein; Sequence Alignment; sulfolobus-solfataricus; Trans-Activators - chemistry; Trans-Activators - classification; Trans-Activators - metabolism; Transcription Factors - chemistry; Transcription Factors - classification; Transcription Factors - metabolism; Transcription, Genetic
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/gkl009

The Lrp/AsnC family of transcriptional regulatory proteins is found in both archaea and bacteria. Members of the family influence cellular metabolism in both a global (Lrp) and specific (AsnC) manner, often in response to exogenous amino acid effectors. In the present study we have determined both the first bacterial and the highest resolution structures for members of the family. Escherichia coli AsnC is a specific gene regulator whose activity is triggered by asparagine binding. Bacillus subtilis LrpC is a global regulator involved in chromosome condensation. Our AsnC-asparagine structure is the first for a regulator–effector complex and is revealed as an octameric disc. Key ligand recognition residues are identified together with a route for ligand access. The LrpC structure reveals a stable octamer supportive of a topological role in dynamic DNA packaging. The structures yield significant clues to the functionality of Lrp/AsnC-type regulators with respect to ligand binding and oligomerization states as well as to their role in specific and global DNA regulation.