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A protein import receptor in pea chloroplasts, Toc86, is only a proteolytic fragment of a larger polypeptide
Author(s) -
Bölter Bettina,
May Timo,
Soll Jürgen
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01525-7
Subject(s) - chloroplast , protein subunit , arabidopsis thaliana , biochemistry , biology , arabidopsis , gene , mutant
The protein import complex of the chloroplastic outer envelope (Toc‐complex) contains a prominent subunit of 86 kDa molecular weight (Toc86). Toc86 was identified as a putative precursor receptor. The Arabidopsis genome sequencing project indicates that Toc86 represents only a proteolytic fragment of a larger polypeptide of 160 kDa. The 160‐kDa protein, which we name Toc160, is only present in significant amounts in pea chloroplasts isolated under stringent conditions. The capacity of chloroplasts to import an in vitro translated precursor protein correlates well with the integrity of Toc160. We conclude that Toc160 is still a bonafide subunit of the protein import machinery of chloroplasts.