5K7F

Crystal structure of apo AibR

5K7F の概要

• エントリーDOI: 10.2210/pdb5k7f/pdb
• 分子名称: Transcriptional regulator, TetR family, ACETATE ION (3 entities in total)
• 機能のキーワード: tetr like regulator, isovalerate, regulation, transcription
• 由来する生物種: Myxococcus xanthus (strain DK 1622)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 51427.75

構造登録者

Bock, T.,Volz, C.,Mueller, R.,Blankenfeldt, W. (登録日: 2016-05-26, 公開日: 2016-12-21, 最終更新日: 2024-05-08)

主引用文献

Bock, T.,Volz, C.,Hering, V.,Scrima, A.,Muller, R.,Blankenfeldt, W.
The AibR-isovaleryl coenzyme A regulator and its DNA binding site - a model for the regulation of alternative de novo isovaleryl coenzyme A biosynthesis in Myxococcus xanthus.
Nucleic Acids Res., 45:2166-2178, 2017

PubMed Abstract: Isovaleryl coenzyme A (IV-CoA) is an important building block of iso-fatty acids. In myxobacteria, IV-CoA is essential for the formation of signaling molecules involved in fruiting body formation. Leucine degradation is the common source of IV-CoA, but a second, de novo biosynthetic route to IV-CoA termed AIB (alternative IV-CoA biosynthesis) was recently discovered in M. xanthus. The AIB-operon contains the TetR-like transcriptional regulator AibR, which we characterize in this study. We demonstrate that IV-CoA binds AibR with micromolar affinity and show by gelshift experiments that AibR interacts with the promoter region of the AIB-operon once IV-CoA is present. We identify an 18-bp near-perfect palindromic repeat as containing the AibR operator and provide evidence that AibR also controls an additional genomic locus coding for a putative acetyl-CoA acetyltransferase. To elucidate atomic details, we determined crystal structures of AibR in the apo, the IV-CoA- and the IV-CoA-DNA-bound state to 1.7 Å, 2.35 Å and 2.92 Å, respectively. IV-CoA induces partial unfolding of an α-helix, which allows sequence-specific interactions between AibR and its operator. This study provides insights into AibR-mediated regulation and shows that AibR functions in an unusual TetR-like manner by blocking transcription not in the ligand-free but in the effector-bound state.

PubMed: 27940564
DOI: 10.1093/nar/gkw1238

実験手法

X-RAY DIFFRACTION (1.7 Å)