Sec/SRP-independent insertion of two thylakoid membrane proteins bearing cleavable signal peptides

Soo Jung Kim, Colin Robinson, Alexandra Mant

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

Two imported thylakoid membrane proteins, PSII-X and PSII-W, are synthesised with cleavable N-terminal signal peptides that closely resemble those of Sec-dependent lumenal proteins. In this report we have reconstituted the insertion of pre-PSII-X and pre-PSII-W into isolated thylakoids. We show that insertion dots not require either nucleoside triphosphates or stromal extracts, both of which are required for Sec- and signal recognition particle (SRP)-dependent targeting mechanisms. Insertion is furthermore unaffected by protease treatments that destroy the known protein translocation apparatus in the thylakoid manbrane. We conclude that these membrane proteins are inserted by an unusual Sec/SRP-independent mechanism that probably resembles that used by CF(o)II, and we discuss possible parallels with the biogenesis of phage M13 procoat.

Original languageEnglish (US)
Pages (from-to)105-108
Number of pages4
JournalFEBS Letters
Volume424
Issue number1-2
DOIs
StatePublished - Mar 6 1998

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Keywords

  • Chloroplast
  • Membrane protein
  • Sec
  • Signal peptide
  • Thylakoid membrane

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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