Structure requirement and identification of a cryptic cleavage site in the mitochondrial processing of a plant F1‐ATPase β‐subunit presequence

FEBS Letters

Boutry, Marc¹  Duby, Geoffrey¹  Degand, Hervé¹ 

[1] Unité de Biochimie Physiologique, Université Catholique de Louvain, Croix du Sud 2–20, B-1348 Louvain-la-Neuve, Belgium

关键词: Mitochondrial import;    Processing;    Cryptic cleavage;    Plant;    Mitochondrial processing peptidase;    F1β;    F1-ATP synthase β-subunit;    MPP;    mitochondrial processing peptidase;    GFP;    green fluorescent protein;   

DOI  :  10.1016/S0014-5793(01)02856-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We sought to determine the structural features involved in the processing of the mitochondrial F₁-ATPase β-subunit (F₁β) presequence (54 residues) from Nicotiana plumbaginifolia. The cleavage efficiency of F₁β presequence mutants linked to the green fluorescent protein (GFP) was evaluated in vivo in tobacco by in situ microscopy and Western blotting. The residue at position −1 (Tyr) was required to be an aromatic residue and the residue at position +2 (Thr) was found to be important for F₁β processing, while, unexpectedly, changing the distal (Arg-15) and proximal (Arg-5) arginine residues did not strongly reduce processing. In addition, results also supported the requirement of a helical structure around the cleavage position. Sequencing of the mature form of a precursor containing the first 30 residues of the F₁β presequence linked to GFP revealed the presence of a cryptic cleavage site between residues 26 and 27, which showed the features of a classical mitochondrial processing site, suggesting dual processing of the F₁β presequence. In vitro processing confirmed these data and showed that processing was sensitive to o-phenanthroline, thus catalyzed by mitochondrial processing peptidase.

【 授权许可】

Unknown