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Abstract：
Prolyl-tRNA synthetases (ProRSs) are unique among aminoacyl-tRNA synthetases (aaRSs) in having two distinct structural architectures across different organisms: prokaryote-like (P-type) and eukaryote/archaeon-like (E-type). Interestingly, Bacillus thuringiensis harbors both types, with P-type (BtProRS1) and E-type ProRS (BtProRS2) coexisting. Despite their differences, both enzymes are constitutively expressed and functional in vivo. Similar to BtProRS1, BtProRS2 selectively charges the P-type tRNAPro and displays higher halofuginone tolerance than canonical E-type ProRS. However, these two isozymes recognize the primary identity elements of the P-type tRNAPro-G72 and A73 in the acceptor stem-through distinct mechanisms. Moreover, BtProRS2 exhibits significantly higher tolerance to stresses (such as heat, hydrogen peroxide, and dithiothreitol) than BtProRS1 does. This study underscores how an E-type ProRS adapts to a P-type tRNAPro and how it may contribute to the bacterium\'s survival under stress conditions.
摘要：
Prolyl-tRNA合成酶（ProRS）在氨酰基-tRNA合成酶（aaRS）中是独特的，在不同生物体中具有两种不同的结构架构：原核生物样（P型）和真核生物/古细菌样（E型）。有趣的是,苏云金芽孢杆菌有两种类型，P型（BtProRS1）和E型ProRS（BtProRS2）共存。尽管存在差异,这两种酶在体内组成型表达和功能。与BtProRS1相似，BtProRS2选择性地为P型tRNAPro充电，并显示出比规范的E型ProRS更高的卤夫酮耐受性。然而,这两种同工酶通过不同的机制识别受体茎中P型tRNAPro-G72和A73的主要身份元件。此外，BtProRS2对应力(如热，过氧化氢,和二硫苏糖醇）比BtProRS1做。这项研究强调了E型ProRS如何适应P型tRNAPro，以及它如何有助于细菌在应激条件下的存活。
