CXI | X-ray Laser Gets First Real-time Snapshots of a Chemical Flipping a Biological Switch

when you think about RNA a key part of

our genetic material

synchronized-swimming probably isn't the

first image that comes to mind

researchers working at SLAC National

Accelerator Laboratory have recently

observed for the first time a molecular

switch in RNA that mimics a water ballet

with millions of segments of RNA

changing shape at the same time in

response to a chemical signal by using

the ultra bright ultra-fast x-ray pulses

produced by slacks Linette coherent

light source the researchers were able

to take atomic level resolution images

of this biochemical interaction in real

time this not only revealed the

previously unseen transition but also

demonstrated that researchers can now

use facilities like the LCLs to study

chemical interactions between

biomolecules a scientific first to study

this interaction the researchers used a

special kind of experimental setup

normally molecular reactions are studied

at the LCLs by using light to trigger

the reaction in a sample and then by

hitting the sample with x-rays from the

LCLs however because this interaction

was chemical in nature the researchers

use two pumps to precisely mix tiny

crystals of the RNA segments called

ribose switches with a special signaling

protein triggering the interaction the

mixture was then hit by an x-ray pulse

from the LCLs where the scattered x-rays

were recorded by a detector and used to

create high-resolution structures of the

rival switches by allowing the

biomolecules to mix for different

periods of time the researchers were

able to take images at different stages

of the process including the surprising

synchronized ballet where all of the

ribose switches drastically changed

shape almost instantaneously after a

short time mixing with the signaling

protein this technique not only unlocks

new information about RNA but also

enables researchers to study many kinds

of biochemical interactions which was

not previously possible at LCLs this

could even open the doors to improve

diagnosis and therapy for things like

cancer and HIV all in all though thanks

to this new technique we may discover

many new forms of molecular ballet and

the surprising results that come from

them

 SLAC National Accelerator Laboratory