ISSN:
1617-4623
Keywords:
Chloroplast protein transport
;
Mutants
;
NPTII fusions
;
Small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase
;
transit peptide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary We compared the transport in vitro of fusion proteins of neomycin phosphotransferase II (NPTII) with either the transit peptide of the small subunit (SSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase or the transit peptide and the 23 aminoterminal amino acids of the mature small subunit. The results showed that the transit peptide is sufficient for import of NPTII. However, transport of the fusion protein consisting of the transit peptide linked directly to NPTII was very inefficient. In contrast, the fusion protein containing a part of the mature SSU was imported with an efficiency comparable to that of the authentic SSU precursor. We conclude from these results that other features of the precursor protein in addition to the transit peptide are important for transport into chloroplasts. In order to identify functional regions in the transit peptide, we analyzed the transport of mutant fusion proteins. We found that the transport of fusion proteins with large deletions in the aminoterminal, or central part was drastically reduced. In contrast, duplication of a part of the transit peptide led to a marked increase in transport.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00338081
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