Transit peptides of nuclear-encoded chloroplast proteins share a common amino acid framework - PubMed (original) (raw)

Transit peptides of nuclear-encoded chloroplast proteins share a common amino acid framework

G A Karlin-Neumann et al. EMBO J. 1986 Jan.

Abstract

We have identified three major blocks of amino acid homology shared by the transit peptides of two nuclear-encoded chloroplast proteins, the light-harvesting chlorophyll a/b-protein (LHCP) II of the thylakoid membrane and the small subunit (SSU) of ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) of the stroma. These previously unrecognized homology blocks lie at the beginning, middle and end of both transit sequences, and are separated by differing lengths of unshared (interblock) sequence in the two proteins. These interblocks may be dispensible or they might confer a specific property on the individual proteins, such as facilitating proper compartmentalization within the chloroplast. We propose that these three shared sequence elements form a common framework in transit-bearing chloroplast precursors which mediates the common functions performed by each transit peptide. Ferredoxin, the only other such nuclear-encoded protein for which a published transit sequence exists, conforms to the predictions of this hypothesis. These findings stand in contrast to mitochondrial leader sequences and the well-studied signal peptides of secretory and certain integral membrane proteins in which no such framework has been observed.

PubMed Disclaimer

Similar articles

Cited by

References

    1. J Biol Chem. 1982 Feb 10;257(3):1558-63 - PubMed
    1. Biochimie. 1984 Jul-Aug;66(7-8):539-45 - PubMed
    1. J Cell Biol. 1979 Jun;81(3):461-83 - PubMed
    1. Biochim Biophys Acta. 1984 Jan 27;779(1):65-87 - PubMed
    1. J Cell Biol. 1981 Nov;91(2 Pt 1):468-78 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources