Characterisation of an Arabidopsis cDNA encoding a thylakoid lumen protein related to a novel 'pentapeptide repeat' family of proteins.
We have cloned an Arabidopsis cDNA encoding a novel thylakoid lumen protein, P17.4, that has been previously isolated from lumen extracts of spinach chloroplasts. The protein is synthesised with a bipartite presequence containing a Sec-type lumen-targeting signal peptide and the precursor protein is imported into the lumen of pea chloroplasts. The encoded protein is homologous to an Anabaena protein that is essential for correct glycolipid localisation, and is also related to at least 16 unassigned open reading frames in Synechocystis. This family of proteins is characterised by the presence of numerous pentapeptide repeats with the consensus structure AXLXX, and its members are predicted to be located in the cytosol, plasma membrane and periplasm/lumen. P17.4 is therefore the first higher plant member of an extended family of putative cyanobacterial proteins that may serve important roles in lipid transport or assembly.
Kieselbach
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T
Arrhenius Laboratory, Department of Biochemistry, Stockholm University, Sweden.
Mant
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A
Robinson
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Schroder
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WP
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins; D002736:Chloroplasts / Q000378:metabolism; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D015388:Organelles / Q000378:metabolism; D018532:Pisum sativum / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D021382:Protein Sorting Signals / Q000096:biosynthesis / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D018724:Spinacia oleracea / Q000378:metabolism
C113195:AT5G53490 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D010940:Plant Proteins; D021382:Protein Sorting Signals; D011994:Recombinant Proteins