%0 Journal Article
%T The universally conserved GTPase HflX is an RNA helicase that restores heat-damaged Escherichia coli ribosomes
%A Biswas
%A Chiranjit
%A Chiranjit Biswas
%A Dey
%A Jayati
%A Jayati Sengupta
%A Sengupta
%A Sip
%A Sip Dey
%J JCB | The Journal of Cell Biology
%D 2018
%R 10.1083/jcb.201711131
%X The ribosome-associated GTPase HflX acts as an antiassociation factor upon binding to the 50S ribosomal subunit during heat stress in Escherichia coli. Although HflX is recognized as a guanosine triphosphatase, several studies have shown that the N-terminal domain 1 of HflX is capable of hydrolyzing adenosine triphosphate (ATP), but the functional role of its adenosine triphosphatase (ATPase) activity remains unknown. We demonstrate that E. coli HflX possesses ATP-dependent RNA helicase activity and is capable of unwinding large subunit ribosomal RNA. A cryo¨Celectron microscopy structure of the 50S¨CHflX complex in the presence of nonhydrolyzable analogues of ATP and guanosine triphosphate hints at a mode of action for the RNA helicase and suggests the linker helical domain may have a determinant role in RNA unwinding. Heat stress results in inactivation of the ribosome, and we show that HflX can restore heat-damaged ribosomes and improve cell survival.
%U http://jcb.rupress.org/content/217/7/2519