Arabidopsis PsbOs differ in their GTPase activity
2008 (English)In: Photosynthesis: Energy from the Sun / [ed] John F. Allen, Elisabeth Gantt, John H. Golbeck, Barry Osmond., Springer , 2008, 729-731 p.Chapter in book (Other academic)
Crucial for the optimal function of the oxygen-evolving complex (OEC) is the PsbO subunit of the photosystem II (PSII) complex. Previously we reported the ability of PsbO in spinach to bind and hydrolyze GTP. GTP stimulates the dissociation of PsbO from PSII following illumination and induces the degradation of the D1 protein. We have predicted four plant-specific binding motifs for GTP, which are not conserved in the sequences of the cyanobacteria or green algae PsbO proteins. We have proposed a location of the GTP-binding site inside the β-barrel exposed to the lumenal side. Arabidopsis thaliana has two PsbO isoforms encoded by two different genes: psbO1 and psbO2. Here we have measured and compared the GTPase activities of PSII membranes isolated from Arabidopsis knockouts mutants containing T-DNA insertions in one or the other of the psbO genes. The specific GTPase activity of PsbO2 is three fold higher than that of PsbO1. Furthermore, PsbO2 is more efficiently released than PsbO1 from PSII following light treatment. We conclude that PsbO2 is a better GTPase than Psb.
Place, publisher, year, edition, pages
Springer , 2008. 729-731 p.
Photosystem II, PsbO protein, Arabidopsis thaliana, T-DNA insertionO1
IdentifiersURN: urn:nbn:se:liu:diva-13006DOI: 10.1007/978-1-4020-6709-9_162ISBN: 978-1-4020-6707-5OAI: oai:DiVA.org:liu-13006DiVA: diva2:17655