Structural Characterization of the D-Tyr-tRNA^TyrDeacylase from <i>Bacillus lichenformis</i>, an Organism of Great Industrial Importance

A new class of enzyme was established that hydrolyze the ester bond between D-Tyr bound onto its cognate t-RNA. The enzyme is called D-Tyr-tRNA deacylase. The three dimensional structure of the D-Tyr-tRNA deacylase from industrially important microorganism Bacillus lichenformis DSM13 was predicted by comparative modeling approach. Since the protein acts as a dimer a dimeric model of the enzyme was constructed. The interactions responsible for dimerization were also predicted. With the help of docking and molecular dynamics simulations the favourable binding mode of the enzyme was predicted. The probable biochemical mechanism of the hydrolysis process was elucidated. This study provides a rational framework to interpret the molecular mechanistic details of the removal of toxic D-Tyr-tRNA from the cells of industrially important microorganism Bacillus lichenformis DSM13 using the enzyme D-Tyr-tRNA deacylase.

D-酪氨酰-tRNA脱酰基酶的研究进展

D-酪氨酰-tRNA脱酰基酶广泛存在于细菌、真核生物、古生菌等多种生物体中,其主要功能是水解D-氨酰-tRNA成游离的D-氨基酸和tRNA,避免D-氨基酸对生物体的毒性,对于不同生物体的生长均有重要作用。D-酪氨酰-tRNA脱酰基酶在不同生物中序列高度保守,使得其水解功能具有一致性及稳定性。D-酪氨酰-tRNA脱酰基酶利用自身的Gly-cis Pro二肽模块识别并排除L-氨基酸,捕获D-氨酰-tRNA,并通过亲核催化反应水解底物产生游离的产物,具有底物选择性。随着近年来研究的深入,科学家研究发现D-酪氨酰-tRNA脱酰基酶具有抑制生物膜分解、增加对乙醇的抗性等特殊功能。文章从D-酪氨酰-tRNA脱酰基酶的种类、晶体结构、催化机制、功能及其应用等方面进行了综述,并在此基础上对D-酪氨酰-tRNA脱酰基酶的应用及功能进行了展望。