6S0M

Structural and dynamic studies provide insights into specificity and allosteric regulation of Ribonuclease AS, a key enzyme in mycobacterial virulence

6S0M の概要

• エントリーDOI: 10.2210/pdb6s0m/pdb
• 分子名称: 3'-5' exoribonuclease, RNA (5'-R(P*G)-3'), MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: ----, rna binding protein
• 由来する生物種: Mycobacterium tuberculosis; 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 39834.80

構造登録者

Berisio, R.,Romano, M. (登録日: 2019-06-17, 公開日: 2019-08-28, 最終更新日: 2024-05-15)

主引用文献

Calvanese, L.,Squeglia, F.,Romano, M.,D'Auria, G.,Falcigno, L.,Berisio, R.
Structural and dynamic studies provide insights into specificity and allosteric regulation of ribonuclease as, a key enzyme in mycobacterial virulence.
J.Biomol.Struct.Dyn., 38:2455-2467, 2020

PubMed Abstract: Ribonuclease AS (RNase AS) is a crucial enzyme for virulence of . We previously observed that RNase AS structurally resembles RNase T from , an important enzyme for tRNA maturation and turnover. Here, we combine X-ray crystallography and molecular dynamics (MD) to investigate the specificity and dynamic properties of substrate binding. Both X-ray and MD data provide structural determinants that corroborate the strict substrate specificity of RNase AS to cleave only adenosine residues, due to the structural features of adenine base. Beside suggesting tRNA as most likely substrate of RNase AS, MD and modeling studies identify key enzyme-ligand interactions, both involving the catalytic site and the double helix region of tRNA, which is locked by interactions with a set of arginine residues. The MD data also evidence a ligand-induced conformational change of the enzyme which is transferred from one chain to the adjacent one. These data will explain the dimeric nature of both RNase AS and RNase T, with two catalytic grooves composed of both chains. Also, they account for the dichotomy of tRNA, which contains both the substrate poly(A) chain and an inhibiting double strand RNA. Indeed, they provide a possible mechanism of allosteric regulation, which unlocks one catalytic groove when the second groove is inhibited by the double strand region of tRNA. Finally, a full comprehension of the molecular details of tRNA maturation processes is essential to develop novel strategies to modulate RNA processing, for therapeutic purposes. AbbreviationsMDmolecular dynamicsPDBProtein Data BankRMSDroot mean square deviationRMSFroot mean square fluctuationRNAribonucleotidic acidRNase ASRibonuclease ASCommunicated by Ramasamy H. Sarma.

PubMed: 31299874
DOI: 10.1080/07391102.2019.1643786

実験手法

X-RAY DIFFRACTION (2 Å)