Details

Autor(en) / Beteiligte

• Mould, R.M
• Knight, J.S
• Bogsch, E
• Gray, J.C

Titel

Azide-sensitive thylakoid membrane insertion of chimeric cytochrome f polypeptides imported by isolated pea chloroplasts

Ist Teil von

• The Plant journal : for cell and molecular biology, 1997-05, Vol.11 (5), p.1051-1058

Ort / Verlag

Osney Mead, Oxford OX2 0EL, UK: Blackwell Science Ltd

Erscheinungsjahr

1997

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Post-translational integration of cytochrome f into thylakoid membranes was observed after import by isolated pea chloroplasts of a chimeric protein consisting of the presequence of the small subunit of ribulose 1,5-bisphosphate carboxylase fused to the cytochrome f precursor. Import of a similar chimeric protein lacking the C-terminal 33 amino acid residues resulted in a soluble cytochrome f protein in the thylakoid lumen, indicating that the C-terminal region contains a stop-transfer sequence for membrane integration. Azide inhibited the insertion of cytochrome f into the thylakoid membrane, whereas the ionophores nigericin and valinomycin had little effect on membrane insertion. The precursor of the 33 kDa protein, but not the 23 kDa protein, of the photosystem II oxygen-evolving complex inhibited the thylakoid insertion of cytochrome f, suggesting competition for a component of the transport pathway. These experiments suggest that the post-translational insertion of cytochrome I into the thylakoid membrane uses a SecA-dependent pathway.