A single point mutation in the C-terminal extension of wheat Rubisco activase dramatically reduces ADP inhibition via enhanced ATP binding affinity.

ABSTRACT: Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activase (Rca) is a AAA⁺ enzyme that uses ATP to remove inhibitors from the active site of Rubisco, the central carboxylation enzyme of photosynthesis. Rca α and β isoforms exist in most higher plant species, with the α isoform being identical to the β form but having an additional 25-45 amino acids at the Rca C terminus, known as the C-terminal extension (CTE). Rca is inhibited by ADP, and the extent of ADP sensitivity of the Rca complex can be modulated by the CTE of the α isoform, particularly in relation to a disulfide bond structure that is specifically reduced by the redox-regulatory enzyme thioredoxin-f. Here, we introduced single point mutations of Lys-428 in the CTE of Rca-α from wheat (Triticum aestivum)

SUBMITTER: Scafaro AP 

PROVIDER: S-EPMC6879333 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature