A second RNA-binding protein is essential for ethanol tolerance provided by the bacterial OLE ribonucleoprotein complex

作     者：Harris, Kimberly A. Zhou, Zhiyuan Peters, Michelle L. Wilkins, Sarah G. Breaker, Ronald R. 

作者机构：Yale Univ Howard Hughes Med Inst New Haven CT 06520 USA Yale Univ Dept Mol Cellular & Dev Biol New Haven CT 06520 USA Yale Univ Dept Mol Biophys & Biochem New Haven CT 06520 USA 

出 版 物：《PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA》 (美国国家科学院汇刊)

年 卷 期：2018年第115卷第27期

页      面：E6319-E6328页

核心收录：

学科分类：07[理学] 08[工学] 

基　　金：NIH [F32G M116426, G MO22778] Howard Hughes Medical Institute 

主　　题：alcohol toxicity Bacillus halodurans noncoding RNA OLE RNA YbzG 

摘      要：OLE (ornate, large, extremophilic) RNAs comprise a class of structured noncoding RNAs (ncRNAs) found in many extremophilic bacteria species. OLE RNAs constitute one of the longest and most widespread bacterial ncRNA classes whose major biochemical function remains unknown. In the Gram-positive alkaliphile Bacillus halodurans, OLE RNA is abundant, and localizes to the cell membrane by association with the transmembrane OLE-associated protein called OapA (formerly OAP). These characteristics, along with the well-conserved sequence and structural features of OLE RNAs, suggest that the OLE ribonucleoprotein (RNP) complex performs important biological functions. B. halodurans strains lacking OLE RNA (Delta ole) or OapA (Delta oapA) are less tolerant of cold (20 degrees C) and shortchain alcohols (e.g., ethanol). Here, we describe the effects of a mutant OapA (called PM1) that more strongly inhibits growth under cold or ethanol stress compared with strains lacking the oapA gene, even when wild-type OapA is present. This dominant-negative effect of PM1 is reversed by mutations that render OLE RNA nonfunctional. This finding demonstrates that the deleterious PM1 phenotype requires an intact RNP complex, and suggests that the complex has one or more additional undiscovered components. A genetic screen uncovered PM1 phenotype suppressor mutations in the ybzG gene, which codes for a putative RNA-binding protein of unknown biological function. We observe that YbzG protein (also called OapB) selectively binds OLE RNA in vitro, whereas a mutant version of the protein is not observed to bind OLE RNA. Thus, YbzG/OapB is an important component of the functional OLE RNP complex in B. halodurans.