Gayle K. Lamppa

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A highly specific stromal processing activity is thought to cleave a large diversity of precursors targeted to the chloroplast, removing an N-terminal transit peptide. The identity of this key component of the import machinery has not been unequivocally established. We have previously characterized a chloroplast processing enzyme (CPE) that cleaves the(More)
We have isolated and characterized a full–length cDNA clone encoding the precursor to the small subunit of wheat ribulose–1,5–bisphosphate carboxylase. From the nucleotide sequence, we deduce that the precursor contains the mature small subunit of 128 amino acid residues and an amino–terminal transit sequence of 47 amino acid residues. Southern blot(More)
A stromal processing peptidase (SPP) cleaves a broad range of precursors targeted to the chloroplast, yielding proteins for numerous biosynthetic pathways in different compartments. SPP contains a signature zinc-binding motif, His-X-X-Glu-His, that places it in a metallopeptidase family which includes the mitochondrial processing peptidase. Here, we have(More)
The stromal processing peptidase (SPP) catalyzes removal of transit peptides from a diversity of precursor proteins imported into chloroplasts. SPP contains an HXXEH zinc-binding motif characteristic of members of the metallopeptidase family M16. We previously found that the three steps of precursor processing by SPP (i.e. transit peptide binding, removal,(More)
Nuclear-encoded proteins targeted to the chloroplast are typically synthesized with N-terminal transit peptides which are proteolytically removed upon import. Structurally related proteins of 145 and 143 kDa copurify with a soluble chloroplast processing enzyme (CPE) that cleaves the precursor for the major light-harvesting chlorophyll a/b binding protein(More)
The stromal processing peptidase (SPP) cleaves a large diversity of chloroplast precursor proteins, removing an N-terminal transit peptide. We predicted previously that this key step of the import pathway is mediated by features of the transit peptide that determine precursor binding and cleavage followed by transit peptide conversion to a degradable(More)
A genomic clone for a major chlorophyll a/b-binding polypeptide of the light-harvesting complex has been sequenced from wheat. This gene, whAB1.6, encodes a 70-nucleotide 5'-nontranslated spacer, a 34-amino-acid NH2-terminal extension, i.e., the transit peptide, and a mature coding protein of 232 amino acid residues. The exact molecular weight of the(More)
Two linked genes, A1 and A2, coding for nearly identical isoforms of the acyl carrier protein (ACP) were isolated from an Arabidopsis thaliana (columbia) genomic library and sequenced. The amino acids deduced from the nucleotide sequence of the two genes indicate they encode distinct transit peptides, but the mature proteins are the same except for residue(More)
The major light-harvesting chlorophyll a/b binding protein (LHCP) of higher plant chloroplasts is nuclear-encoded, synthesized as a precursor, and processed upon import. We have previously (GK Lamppa, M Abad [1987] J Cell Biol 105: 2641-2648) identified a soluble enzyme that cleaves the LHCP precursor (pLHCP). In this study, we describe the conditions for(More)
Two proteins of 145 and 143 kDa were identified in pea which co-purify with a chloroplast processing activity that cleaves the precursor for the major light-harvesting chlorophyll binding protein (preLHCP). Antiserum generated against the 145/143 kDa doublet recognizes only these two polypeptides in a chloroplast soluble extract. In immunodepletion(More)