2IVM

Crystal structure of a transcriptional regulator

2IVM の概要

• エントリーDOI: 10.2210/pdb2ivm/pdb
• 分子名称: TRANSCRIPTIONAL REGULATORY PROTEIN (2 entities in total)
• 機能のキーワード: transcriptional regulator, transcription
• 由来する生物種: MYCOBACTERIUM TUBERCULOSIS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 33033.14

構造登録者

Shrivastava, T.,Ramachandran, R. (登録日: 2006-06-14, 公開日: 2007-10-09, 最終更新日: 2024-05-08)

主引用文献

Shrivastava, T.,Ramachandran, R.
Mechanistic Insights from the Crystal Structures of a Feast/Famine Regulatory Protein from Mycobacterium Tuberculosis H37Rv.
Nucleic Acids Res., 35:7324-, 2007

PubMed Abstract: Rv3291c gene from Mycobacterium tuberculosis codes for a transcriptional regulator belonging to the (leucine responsive regulatory protein/regulator of asparigine synthase C gene product) Lrp/AsnC-family. We have identified a novel effector-binding site from crystal structures of the apo protein, complexes with a variety of amino acid effectors, X-ray based ligand screening and qualitative fluorescence spectroscopy experiments. The new effector site is in addition to the structural characterization of another distinct site in the protein conserved in the related AsnC-family of regulators. The structures reveal that the ligand-binding loops of two crystallographically independent subunits adopt different conformations to generate two distinct effector-binding sites. A change in the conformation of the binding site loop 100-106 in the B subunit is apparently necessary for octameric association and also allows the loop to interact with a bound ligand in the newly identified effector-binding site. There are four sites of each kind in the octamer and the protein preferentially binds to aromatic amino acids. While amino acids like Phe, Tyr and Trp exhibit binding to only one site, His exhibits binding to both sites. Binding of Phe is accompanied by a conformational change of 3.7 A in the 75-83 loop, which is advantageously positioned to control formation of higher oligomers. Taken together, the present studies suggest an elegant control mechanism for global transcription regulation involving binding of ligands to the two sites, individually or collectively.

PubMed: 17962306
DOI: 10.1093/NAR/GKM850

実験手法

X-RAY DIFFRACTION (2.5 Å)