Premium
Import inhibition of poly(His) containing chloroplast precursor proteins by Ni 2+ ions
Author(s) -
Rothen R.,
Thiess M.,
Schumann P.,
Boschetti A.
Publication year - 1996
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 - 10.1016/0014-5793(96)01085-x
Subject(s) - chloroplast , chlamydomonas , rubisco , protein subunit , chemistry , protease , biochemistry , histidine , biophysics , enzyme , biology , mutant , gene
The precursor of the small subunit of ribulose‐1,5‐bisphosphate carboxylase (pSS) and a modified pSS containing a C‐terminal hexahistidyl tail (pSS(His) 6 ) were imported into isolated Chlamydomonas chloroplasts with comparable efficiency. In the presence of Ni 2+ ions the import of pSS(His) 6 was inhibited and the precursor bound to the envelope remained protease sensitive, while import of pSS was not affected. Addition of an excess of l ‐histidine suppressed the inhibition demonstrating that the hexahistidyl‐Ni 2+ complex was responsible for import inhibition. Inhibition could be observed between about 0.5 and 10 mM Ni 2+ , depending on the total protein content in the assay. Import incompetent Ni 2+ ‐precursor complexes can be used to study early events in chloroplast protein import.