An Arabidopsis thaliana cDNA encoding PS II-X, a 4.1 kDa component of photosystem II: A bipartite presequence mediates SecA/Delta pH-independent targeting into thylakoids
UNSPECIFIED. (1996) An Arabidopsis thaliana cDNA encoding PS II-X, a 4.1 kDa component of photosystem II: A bipartite presequence mediates SecA/Delta pH-independent targeting into thylakoids. FEBS LETTERS, 390 (2). pp. 175-178. ISSN 0014-5793Full text not available from this repository.
Higher plant photosystem II preparations contain a 4.1 kDa polypeptide (subunit X) associated with the oxygen-evolving core complex, We describe the isolation of a cDNA encoding PS II-X from Arabidopsis thaliana, in which the C-terminal region is highly homologous to partially sequenced PS II-X from wheat and spinach, The mature protein of 42 residues is preceded by a 74-residue, bipartite presequence similar to those involved in the targeting of nuclear-encoded thylakoid lumen proteins, although hydrophobicity analysis indicates the presence of a single transmembrane span in the mature protein, Moreover, import of pre-PS II-X into the thylakoid membrane of isolated chloroplasts is unaffected by inhibitors of either the Sec- or Delta pH-dependent thylakoidal protein translocases, suggesting a spontaneous insertion mechanism, PS II-X appears to be encoded as a mature protein by the plastid genome in the chlorophyll a+c-containing alga, Odontella sinensis. We thus propose that the thylakoid transfer signal of Arabidopsis pre-PS II-X represents a recent acquisition, in phylogenetic terms, compared with signals of Sec-dependent lumenal proteins.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
Q Science > QH Natural history > QH301 Biology
|Journal or Publication Title:||FEBS LETTERS|
|Publisher:||ELSEVIER SCIENCE BV|
|Date:||22 July 1996|
|Number of Pages:||4|
|Page Range:||pp. 175-178|
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