NOV 17, 2022 8:00 AM PST

The evolution of carbon fixation: Studying Form I Rubisco using ancestral sequence reconstruction and mass photometry

Sponsored by: Refeyn
C.E. Credits: P.A.C.E. CE Florida CE
Speaker

Abstract
Date:  November 17, 2022
Time: 8:00am (PST),  11:00am (EST), 5:00pm (CET)
 
Up to now, the evolutionary trajectory of the most prevalent CO2-fixing enzyme – Rubisco Form I, has been difficult to study. The Rubisco found in today’s plants and algae has 8 small subunits (SSU) that are absent from its ancestral form. The SSU has become essential for the enzyme’s solubility and activity, hindering biochemical studies into its influence on Rubisco. Our research aimed to decipher how the obligate interaction between Rubisco and its SSU evolved. This includes identifying the functional implications of Rubisco interacting with the SSU, discovering why the modern Rubisco depends on the SSU, as well as how the SSU modulated the evolutionary trajectories available to Rubisco. To address these questions, we combined ancestral sequence reconstruction and mass photometry. We re-created a long-extinct evolutionary precursor of modern Rubiscos, which interacts with the SSU but does not depend on it. With this intermediate, we show that Rubisco increased its specificity and carboxylation efficiency through the gain of a new accessory subunit before atmospheric oxygen was present.
Mass photometry enabled us to narrow down the evolutionary interval over which Rubisco’s oligomerization state changed. It also made it possible to screen for the substitutions that caused Rubisco’s dependence on the SSU for solubility.
We show that the current form of Rubisco evolved from an octamer of large subunits that started to interact with the SSU more than 2.5 billion years ago. Immediately upon recruitment, the SSU improved Rubiscos catalysis and specificity. Then, a substitution made Rubisco dependent on the SSU for solubility. Our work sheds light on the emergence of an adaptation to rising ambient oxygen levels, provides a template for investigating the function of interactions that have remained elusive because of their essentiality, and sheds new light on the determinants of specificity in Rubisco.
 
Learning Objectives
  • To explain how a protein-protein interaction can re-shape the sequence space that is available to a protein during its evolution.
  • To understand why hetero-oligomeric proteins start to depend on their interaction partners over the course of evolution.
  • To learn how mass photometry can be used to re-trace the emergence of a protein-protein interaction.
  • To understand how a small protein with no obvious link to catalysis can influence the function of an enzyme.
 
 
Webinars will be available for unlimited on-demand viewing after live event.
 
LabRoots is approved as a provider of continuing education programs in the clinical laboratory sciences by the ASCLS P.A.C.E. ® Program. By attending this webinar, you can earn 1 Continuing Education credit once you have viewed the webinar in its entirety.

Show Resources
You May Also Like
JUN 21, 2022 6:00 AM PDT
JUN 21, 2022 6:00 AM PDT
Date: June 21, 2022 Time: 6:00am (PDT), 9:00am (EDT), 3:00pm (CEST) The global understanding and practice of medicine is currently undergoing a revolutionary change. This shift to precision...
JUN 28, 2022 7:00 AM PDT
JUN 28, 2022 7:00 AM PDT
Date: June 28, 2022 Time: 3:00pm (BST), 4:00pm (CET), 9:00am (CST), 7am (PST) Light-sheet microscopy is an extremely versatile imaging technique with a vast range of implementations that are...
AUG 24, 2022 7:00 AM PDT
AUG 24, 2022 7:00 AM PDT
Date: August 24, 2022 Time: 7:00am (PDT), 10:00pm (EDT), 4:00pm (CEST) Light field microscopy was first introduced in 2006, and allows users to capture the 4D light field within the microsco...
JUL 19, 2022 8:00 AM PDT
C.E. CREDITS
JUL 19, 2022 8:00 AM PDT
Date: July 19, 2022 Time: 8:00am (PDT), 11:00am (EDT), 5:00pm (CEST) Cryo-EM is rapidly becoming the method of choice for structural biologists and biochemists around the world, helping thes...
OCT 13, 2022 9:00 AM +08
OCT 13, 2022 9:00 AM +08
First Broadcast: Date: October 12, 2022 Time: 8:00am PDT, 11:00am EDT Second Broadcast: Date: October 12, 2022 Time: 9:00am SGT The new Embedded CryoSPARC Live, now fully integrated with t...
AUG 10, 2022 10:00 AM PDT
AUG 10, 2022 10:00 AM PDT
Date: August 10, 2022 Time: 10:00am PDT, 1:00pm EDT The global pandemic has increased focus and scrutiny on molecular diagnostic assay development, resulting in a need for assays that provid...
Loading Comments...
Show Resources