Biochemical Studies Provide Insights into the Necessity for Multiple Arabidopsis thaliana Protein-Only RNase P Isoenzymes

JOURNAL OF MOLECULAR BIOLOGY

卷:431

Article

Chen, Tien-Hao^1,2  Sotomayor, Marcos¹  Gopalan, Venkat^1,2 

[1] Ohio State Univ, Dept Chem & Biochem, Columbus, OH 43210 USA

[2] Ohio State Univ, Ctr RNA Biol, Columbus, OH 43210 USA

关键词: PRORP;    tRNA maturation;    substrate recognition;    temperature activity profiles;    molecular dynamics;   

DOI  :  10.1016/j.jmb.2018.11.004

来源: Elsevier

【 摘 要 】

RNase P catalyzes removal of the 5' leader from precursor tRNAs (pre-tRNAs) in all three domains of life. Some eukaryotic cells contain multiple forms of the protein-only RNase P (PRORP) variant, prompting efforts to unravel this seeming redundancy. Previous studies concluded that there were only modest differences in the processing of typical pre-tRNAs by the three isoforms in Arabidopsis thaliana [AtPRORP1 (organellar), AtPRORP2 and AtPRORP3 (nuclear)]. Here, we investigated if different physical attributes of the three isoforms might engender payoffs under specific conditions. Our temperature-activity profiling studies revealed that AtPRORPs display substrate-identity dependent behavior at elevated temperatures (37-45 degrees C), with the organellar variant outperforming the nuclear counterparts. Echoing these findings, molecular dynamics simulations revealed that AtPRORP2 relative to AtPRORP1 samples a wider conformational ensemble that deviates from the crystal structure. Results from our biochemical studies and molecular dynamics simulations support the idea that AtPRORPs have overlapping but not necessarily redundant attributes and inspire new perspectives on the suitability of each variant to perform its function(s) in a specific cellular locale. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free