A Bacterial Form I' Rubisco Has a Smaller Carbon Isotope Fractionation than Its Form I Counterpart.

ABSTRACT: Form I rubiscos evolved in Cyanobacteria ≥ 2.5 billion years ago and are enzymatically unique due to the presence of small subunits (RbcS) capping both ends of an octameric large subunit (RbcL) rubisco assembly to form a hexadecameric (L₈S₈) holoenzyme. Although RbcS was previously thought to be integral to Form I rubisco stability, the recent discovery of a closely related sister clade of octameric rubiscos (Form I'; L₈) demonstrates that the L₈ complex can assemble without small subunits (Banda et al. 2020). Rubisco also displays a kinetic isotope effect (KIE) where the 3PG product is depleted in ¹³C relative to ¹²C. In Cyanobacteria, only two Form I KIE measurements exist, making interpretation of bacterial carbon isotope

SUBMITTER: Wang RZ 

PROVIDER: S-EPMC10135865 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature