Bacterial ribonuclease E (RNase E) plays a crucial role in the processing and decay of RNAs. A small protein named RraA negatively regulates the activity of RNase E via protein-protein interaction in various bacteria. Recently, RraAS1 and RraAS2, which are functional homologs of RraA from Escherichia coli, were identified in the Gram-positive species Streptomyces coelicolor. RraAS1 and RraAS2 inhibit RNase ES ribonuclease activity in S. coelicolor. RraAS1 and RraAS2 have a C-termi-nal extension region unlike typical bacterial RraA proteins. In this study, we present the crystal structure of RraAS2, ex-hibiting a hexamer arranged in a dimer of trimers, consistent with size exclusion chromatographic results. Importantly, the C-terminal extension region formed a long α-helix at the junction of the neighboring subunit, which is similar to the trimeric RraA orthologs from Saccharomyces cerevisiae. Trun-cation of the C-terminal extension region resulted in loss of RNase ES inhibition, demonstrating its crucial role. Our find-ings present the first bacterial RraA that has a hexameric assembly with a C-terminal extension α-helical region, which plays an essential role in the regulation of RNase ES activity in S. coelicolor.
Citations
Citations to this article as recorded by
Relaxed Cleavage Specificity of Hyperactive Variants of Escherichia coli RNase E on RNA I Dayeong Bae, Hana Hyeon, Eunkyoung Shin, Ji-Hyun Yeom, Kangseok Lee Journal of Microbiology.2023; 61(2): 211. CrossRef
An oxidative metabolic pathway of 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEHU) from alginate in an alginate-assimilating bacterium Ryuji Nishiyama, Takao Ojima, Yuki Ohnishi, Yasuhiro Kumaki, Tomoyasu Aizawa, Akira Inoue Communications Biology.2021;[Epub] CrossRef
The coordinated action of RNase III and RNase G controls enolase expression in response to oxygen availability in Escherichia coli Minho Lee, Minju Joo, Minji Sim, Se-Hoon Sim, Hyun-Lee Kim, Jaejin Lee, Minkyung Ryu, Ji-Hyun Yeom, Yoonsoo Hahn, Nam-Chul Ha, Jang-Cheon Cho, Kangseok Lee Scientific Reports.2019;[Epub] CrossRef
RNase G controls tpiA mRNA abundance in response to oxygen availability in Escherichia coli Jaejin Lee, Dong-Ho Lee, Che Ok Jeon, Kangseok Lee Journal of Microbiology.2019; 57(10): 910. CrossRef
Functional implications of hexameric assembly of RraA proteins from Vibrio vulnificus Saemee Song, Seokho Hong, Jinyang Jang, Ji-Hyun Yeom, Nohra Park, Jaejin Lee, Yeri Lim, Jun-Yeong Jeon, Hyung-Kyoon Choi, Minho Lee, Nam-Chul Ha, Kangseok Lee, Eric Cascales PLOS ONE.2017; 12(12): e0190064. CrossRef