Chlamydomonas reinhardtii

Starch defines a semicrystalline polymer made of two different polysaccharide fractions. The A- and B-type crystalline lattices define the distinct structures reported in cereal and tuber starches, respectively. Amylopectin, the major fraction of starch, is thought to be chiefly responsible for this semicrystalline organization while amylose is generally considered as an amorphous polymer with little or no impact on the overall crystalline organization.

11p system191 01-06-2013 47 4   Download

The physiological role of sulfoquinovosyl diacylglycerol (SQDG) in photosynthesis was investigated with a SQDG defective mutant (hf-2) of Chlamydomonas reinhardtii that did not have any detectable amount of SQDG. The mutant showed a lower rate of photosystem II (PSII) activity by  40% and also a lower growth rate than those of the wildtype. Results of genetical analysis of hf-2 strongly suggest that the SQDG defect and the lowered PSII activity are due to a single gene mutation.

6p research12 01-06-2013 37 6   Download

Chlamydomonas reinhardtii, a unicellular green alga, contains a hydrogenase enzyme, which is induced by anaerobic adaptation of the cells. Using the suppression subtractive hybridization (SSH) approach, the differential expression of genes under anaerobiosis was analyzed. A PCR fragment with similarity to the genes of bacterial Fe-hydrogenases was isolated and used to screen an anaerobic cDNA expression library of C. reinhardtii.

11p research12 01-06-2013 42 6   Download

All living organisms contain redox systems involving thior-edoxins (Trx), proteins featuringanextremelyconservedand reactive active site that perform thiol-disul®de interchanges with disul®de bridges of target proteins. In photosynthetic organisms, numerous isoforms of Trx coexist, as revealedby sequencing ofArabidopsisgenome. The speci®c functions of many of them are still unknown.

11p research12 29-04-2013 34 2   Download

We have isolated and characterized a second [Fe]-hydro-genasegene fromthegreenalga,Chlamydomonas reinhardtii. TheHydA2gene encodes a protein of 505 amino acids that is 74% similar and 68% identical to the known HydA1 hydrogenase fromC. reinhardtii.HydA2 contains all the conserved residues and motifs found in the catalytic core of the family of [Fe]-hydrogenases. We demonstrate that both theHydA1and theHydA2transcripts are expressed upon anaerobic induction, achieved either by neutral gas purging or by sulfur deprivation of the cultures. ...

9p fptmusic 16-04-2013 48 2   Download

The composition of the chloroplast-localized protease complex, ClpP, from the green alga Chlamydomonas reinhardtiiwas characterized by nondena-turing electrophoresis, immunoblotting and MS. The detected ClpP complex has a native mass of
540 kDa, which is
200 kDa higher than ClpP complexes in higher plant chloroplasts, mitochondria or bacteria. The 540-kDa ClpP complex contains two nuclear-encoded ClpP proteins (ClpP3 and P5) and five ClpR (R1, R2, R3, R4 and R6) proteins, as well two pro-teins, ClpP1Land ClpP1H, both probably derived from the plastid clpP1 gene. ...

14p fptmusic 12-04-2013 44 3   Download

The State 1 to State 2 transition in the photosynthetic membranes of plants and green algae involves the functional coupling of phosphorylated light-harvesting complexes of photosystem II (LHCII) to photosystem I (PSI). We present evidence suggesting that inChlamydomonas reinhardtiithis coupling may be aided by a hyper-phosphorylated form of the LHCII-like CP29 protein (Lhcbm4).

10p fptmusic 12-04-2013 36 2   Download

The glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in the chloroplast ofChlamydomonas reinhardtiiis part of a complex that also includes phosphoribulokinase (PRK) and CP12. We identified two residues of GAPDH involved in protein–protein interactions in this complex, by changing residuesK128 andR197 intoAorE.K128A/Emutants had aKmfor NADH that was twice that of the wild type and a lower catalytic constant, whatever the cofactor.

8p awards 05-04-2013 33 3   Download

To test thioredoxin resistance to oxidizing free radicals, we have studied the one-electron oxidation of wild-type thio-redoxin and of two forms with the point mutations D30A and W35A, using azide radicals generated byc-ray or pulse radiolysis. The oxidation patterns of wild-type thioredoxin and D30A are similar. In these forms, Trp35 is the primary target and is
repaired by one-electron reduction; first by intramolecular electron transfer from tyrosine, and then fromother residues. Conversely, duringoxidationofW35A, Trp13 is poorly reactive.

7p awards 05-04-2013 39 4   Download

Sulfoquinovosyl diacylglycerol (SQDG) is involved in the maintenance of photosystem II (PSII) activity in Chlamydomonas reinhardtii[Minoda, A., Sato, N., Nozaki, H., Okada, K., Takahashi, H., Sonoike, K. & Tsuzuki, M. et al.(2002) Eur. J. Biochem.269, 2353–2358]. To under-stand the spread of the taxa in which PSII interacts with SQDG, especially in cyanobacteria, we produced a mutant defective in the putativesqdBgene responsible for SQDG synthesis from two cyanobacteria, Synechocystis sp.

9p dell39 03-04-2013 47 3   Download

Two mutants ofChlamydomonas reinhardtii, mf1andmf2, characterized by a marked reduction in their phosphatidyl-glycerol content together with a complete loss in itsD 3 -trans hexadecenoic acid-containing form, also lost photosystemII (PSII) activity. Genetic analysis of crosses betweenmf2and wild-type strains shows a strict cosegregationof thePSII and lipid deficiencies, while phenotypic analysis of phototrophic revertant strains suggests that one single nuclear mutation is responsible for the pleiotropic phenotype of the mutants....

10p dell39 03-04-2013 54 3   Download

Group I intron ribozymes require cations for folding and catalysis, and the current literature indicates that a number of cations can promote folding, but only Mg 2+ and Mn 2+ support both processes. However, some group I introns are active only with Mg 2+ , e.g. three of the five group I introns in Chlamydomonas reinhardtii. We have investigated one of these ribozymes, an intron from the 23S LSU rRNA gene of Chlamydomonas reinhardtii (Cr.LSU), by determining if the inhibition by Mn 2+ involves catalysis, folding, or both....

14p inspiron33 26-03-2013 47 3   Download

he 8.5 kDa chloroplast protein CP12 is essential for assembly of the phosphoribulokinase⁄glyceraldehyde-3-phosphate dehydrogenase (GAPDH) complex fromChlamydomonas reinhardtii. After reduction of this complex with thioredoxin, phosphoribulokinase is released but CP12 remains tightly associated with GAPDH and downregulates its NADPH-dependent activity.

12p inspiron33 25-03-2013 38 4   Download

Possible binding proteins of CP12 in a green alga,Chlamydomonas rein-hardtii, were investigated. We covalently immobilized CP12 on a resin and then used it to trap CP12 partners. Thus, we found an association between CP12 and phosphoribulokinase (EC 2.7.1.19), glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.13) and aldolase.

12p media19 06-03-2013 47 3   Download

Quang hợp tạo ra thức ăn mà chúng ta tiêu thụ và ôxy mà chúng ta thở liệu có giúp giải quyết nhu cầu năng lượng trong tương lai bằng cách tạo hydro cháy sạch? Các nhà khoa học đang nghiên cứu loại tảo xanh đơn bào tạo ra hydro, Chlamydomonas reinhardtii, đã phát hiện một cách lên men mới có thể mở ra khả năng tăng sản lượng hydro. C. reinhartii, sống trong đất, tạo ra một lượng nhỏ hydro khi mất đi oxy. Giống như men và các vi khuẩn khác, dưới điều kiện kỵ khí loại tảo...

4p nkt_bibo42 05-02-2012 62 5   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Inorganic polyphosphate occurs in the cell wall of Chlamydomonas reinhardtii and accumulates during cytokinesis

11p panasonic06 26-12-2011 54 6   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Characterization of singlet oxygen-accumulating mutants isolated in a screen for altered oxidative stress response in Chlamydomonas reinhardtii

13p panasonic02 14-12-2011 56 3   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Using single cell cultivation system for on-chip monitoring of the interdivision timer in Chlamydomonas reinhardtii cell cycle

13p toshiba25 08-12-2011 58 4   Download