Post-transcriptional steps involved in the assembly of photosystem I in Chlamydomonas

2004 ◽  
Vol 32 (4) ◽  
pp. 567-570 ◽  
Author(s):  
J.-D. Rochaix ◽  
K. Perron ◽  
D. Dauvillée ◽  
F. Laroche ◽  
Y. Takahashi ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Photosystem I ◽  
Protein Complexes ◽  
High Molecular Mass ◽  
Reaction Centre ◽  
Photosynthetic Organisms ◽  
Initiation Of Translation ◽  
Functional Complex ◽  
Rna Protein Complexes ◽  
Photosystem I Complex

Assembly of the PSI (photosystem I) complex in eukaryotic photosynthetic organisms depends on the concerted interactions of the nuclear and chloroplast genetic systems. We have identified several nucleus-encoded factors of Chlamydomonas reinhardtii that are specifically required for the synthesis of the two large chloroplast-encoded reaction-centre polypeptides, PsaA and PsaB, of photosystem I and that function at plastid post-transcriptional steps. Raa1, Raa2 and Raa3 are required for the splicing of the three discontinuous psaA precursor transcripts; they are part of large RNA–protein complexes that are reminiscent of spliceosomal particles. Tab1 and Tab2 are involved in the initiation of translation of the psaB mRNA and are localized in the membrane and stromal phases of the chloroplast, where they are associated with high-molecular-mass complexes. Moreover, two chloroplast-encoded proteins, Ycf3 and Ycf4, are required for the primary steps of assembling the photosystem I subunits into a functional complex.

scholarly journals Entrapment of high-molecular-mass DNA molecules in liposomes for the genetic transformation of animal cells

1989 ◽  
Vol 259 (2) ◽  
pp. 549-553 ◽  
Author(s):  
J Szelei ◽  
E Duda
Keyword(s):  
Genetic Transformation ◽  
Molecular Mass ◽  
Mammalian Cells ◽  
Protein Complexes ◽  
Significant Proportion ◽  
High Molecular Mass ◽  
Marker Genes ◽  
Dna Molecules ◽  
Animal Cells ◽  
Integrity Of Dna

We modified the Ca/EDTA procedure for the production of liposomes [Papahadjopoulos, Vail, Jacobson & Poste (1975) Biochim. Biophys. Acta 394, 483-491] to entrap intact DNA molecules of very high molecular mass into large unilamellar phospholipid vesicles. The use of DNA-protein complexes and phage particles instead of naked linear DNA increases the efficiency of entrapment and protects the integrity of DNA molecules. We investigated the interaction of mammalian cells with liposome-encapsulated recombinant lambda bacteriophages carrying marker genes. The liposomes bind surprisingly fast to the cellular surface and are taken up by the cells. A significant proportion of the encapsulated DNA is transported to and soon located in or around the nuclei. Experiments prove that these liposomes can be used for the genetic transformation of mammalian cells.

scholarly journals Two DEAD-Box Proteins May Be Part of RNA-Dependent High-Molecular-Mass Protein Complexes in Arabidopsis Mitochondria

2007 ◽  
Vol 145 (4) ◽  
pp. 1637-1646 ◽  
Author(s):  
Annemarie Matthes ◽  
Stephanie Schmidt-Gattung ◽  
Daniela Köhler ◽  
Joachim Forner ◽  
Steffen Wildum ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Protein Complexes ◽  
High Molecular Mass ◽  
Dead Box

scholarly journals Ethylene Receptors Function as Components of High-Molecular-Mass Protein Complexes in Arabidopsis

PLoS ONE ◽  
2010 ◽  
Vol 5 (1) ◽  
pp. e8640 ◽  
Author(s):  
Yi-Feng Chen ◽  
Zhiyong Gao ◽  
Robert J. Kerris ◽  
Wuyi Wang ◽  
Brad M. Binder ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Protein Complexes ◽  
High Molecular Mass ◽  
Ethylene Receptors

scholarly journals The epididymal soluble prion protein forms a high-molecular-mass complex in association with hydrophobic proteins

2005 ◽  
Vol 392 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Heath Ecroyd ◽  
Maya Belghazi ◽  
Jean-Louis Dacheux ◽  
Jean-Luc Gatti
Keyword(s):  
Molecular Mass ◽  
Prion Protein ◽  
Hydrophobic Interactions ◽  
Protein Complexes ◽  
Biochemical Properties ◽  
High Molecular Mass ◽  
Soluble Form ◽  
Disulphide Bonds ◽  
Apolipoprotein J ◽  
Associated Proteins

We have shown previously that a ‘soluble’ form of PrP (prion protein), not associated with membranous vesicles, exists in the male reproductive fluid [Ecroyd, Sarradin, Dacheux and Gatti (2004) Biol. Reprod. 71, 993–1001]. Attempts to purify this ‘soluble’ PrP indicated that it behaves like a high-molecular-mass complex of more than 350 kDa and always co-purified with the same set of proteins. The main associated proteins were sequenced by MS and were found to match to clusterin (apolipoprotein J), BPI (bacterial permeability-increasing protein), carboxylesterase-like urinary excreted protein (cauxin), β-mannosidase and β-galactosidase. Immunoblotting and enzymatic assay confirmed the presence of clusterin and a cauxin-like protein and showed that a 17 kDa hydrophobic epididymal protein was also associated with this complex. These associated proteins were not separated by a high ionic strength treatment but were by 2-mercaptoethanol, probably due to its action on reducing disulphide bonds that maintain the interaction of components of the complex. Our results suggest that the associated PrP retains its GPI (glycosylphosphatidylinositol) anchor, in contrast with brain-derived PrP, and that it is resistant to cleavage by phosphatidylinositol-specific phospholipase C. Based on these results, the identity of the associated proteins and the overall biochemical properties of this protein ensemble, we suggest that ‘soluble’ PrP can form protein complexes that are maintained by hydrophobic interactions, in a similar manner to lipoprotein vesicles or micellar complexes.

scholarly journals Identities of four low-molecular-mass subunits of the photosystem I complex fromAnabaena variabilisATCC 29413

FEBS Letters ◽  
1991 ◽  
Vol 287 (1-2) ◽  
pp. 5-9 ◽  
Author(s):  
Masahiko Ikeuchi ◽  
Karin J. Nyhus ◽  
Yorinao Inoue ◽  
Himadri B. Pakrasi
Keyword(s):  
Molecular Mass ◽  
Photosystem I ◽  
Photosystem I Complex

scholarly journals Consequences of impaired 1-MDa TIC complex assembly for the abundance and composition of chloroplast high-molecular mass protein complexes

PLoS ONE ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. e0213364 ◽  
Author(s):  
Peter Schäfer ◽  
Stefan Helm ◽  
Daniel Köhler ◽  
Birgit Agne ◽  
Sacha Baginsky
Keyword(s):  
Molecular Mass ◽  
Protein Complexes ◽  
High Molecular Mass ◽  
Complex Assembly

scholarly journals Type I photosynthetic reaction centres: structure and function

2003 ◽  
Vol 358 (1429) ◽  
pp. 231-243 ◽  
Author(s):  
Peter Heathcote ◽  
Michael R. Jones ◽  
Paul K. Fyfe
Keyword(s):  
Photosystem I ◽  
Type I ◽  
Strictly Anaerobic ◽  
Reaction Centre ◽  
Sequence Alignments ◽  
Reaction Centres ◽  
Green Sulphur Bacteria ◽  
Sulphur Bacteria ◽  
Green Sulphur ◽  
Photosystem I Complex

We review recent advances in the study of the photosystem I reaction centre, following the determination of a spectacular 2.5 Å resolution crystal structure for this complex of Synechococcus elongatus . Photosystem I is proving different to type II reaction centres in structure and organization, and the mechanism of transmembrane electron transfer, and is providing insights into the control of function in reaction centres that operate at very low redox potentials. The photosystem I complex of oxygenic organisms has a counterpart in non–oxygenic bacteria, the strictly anaerobic phototrophic green sulphur bacteria and heliobacteria. The most distinctive feature of these type I reaction centres is that they contain two copies of a large core polypeptide (i.e. a homodimer), rather than a heterodimeric arrangement of two related, but different, polypeptides as in the photosystem I complex. To compare the structural organization of the two forms of type I reaction centre, we have modelled the structure of the central region of the reaction centre from green sulphur bacteria, using sequence alignments and the structural coordinates of the S. elongatus Photosystem I complex. The outcome of these modelling studies is described, concentrating on regions of the type I reaction centre where important structure–function relationships have been demonstrated or inferred.

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