東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Assembly of light-harvesting complex...

Eggink, Laura Lynne.

Linked to FindBook

Google Book

Amazon

博客來

Assembly of light-harvesting complexes in Chlamydomonas reinhardtii.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Assembly of light-harvesting complexes in Chlamydomonas reinhardtii./
Author:	Eggink, Laura Lynne.
Description:	99 p.
Notes:	Adviser: J. Kenneth Hoober.
Contained By:	Dissertation Abstracts International64-03B.
Subject:	Biology, Botany. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3084616

Assembly of light-harvesting complexes in Chlamydomonas reinhardtii.
Eggink, Laura Lynne.

Assembly of light-harvesting complexes in Chlamydomonas reinhardtii. - 99 p.

Adviser: J. Kenneth Hoober.

Thesis (Ph.D.)--Arizona State University, 2003.

Light-harvesting complexes (LHCs) are nuclear-encoded integral proteins in thylakoid membranes that collect and regulate delivery of exciton energy to photosynthetic reaction centers. Pigments, chlorophylls (Chl) <italic> a</italic> and <italic>b</italic> along with active xanthophylls, are required co-factors in assembly and function of LHCs. To investigate the <italic>in vivo</italic> site and mechanism of assembly of LHCs, the model organism, <italic> Chlamydomonas reinhardtii</italic>, was used for this study. Chl <italic> a</italic> and Chl <italic>b</italic> differ only in oxidation of the 7-methyl group of Chl <italic>a</italic> to a formyl group. Chlorophyll(ide) <italic> a</italic> oxygenase, the enzyme responsible for the oxidation, is membrane-associated and located on the inner envelope and thylakoid membranes, as shown by western blotting and immunoelectron microscopy. Conversion of the methyl group may be initiated by a radical, located on a conserved tyrosine, as shown by electron paramagnetic resonance. The ability of Chl <italic>b</italic> to form stronger coordination bonds with amino acid sidechains of the apoproteins of LHCs shifts equilibrium positions of complex formation toward assembly of LHCs in chloroplasts. In <italic>C. reinhardtii</italic>, Chl <italic>b</italic> is required for the import and retention of LHCs by the chloroplast. If Chl <italic> b</italic> is not available during import, assembly does not proceed and LHC apoproteins are shunted to cytoplasmic vacuoles. Molecular modeling of a highly conserved amino acid region within the apoprotein of LHCs, Glu-X-X-His/Asn-X-Arg, suggested that this motif may bind two molecules of Chl. The prediction was confirmed experimentally, which suggests that this motif may bind Chl during the import of LHCs. To indicate the importance of the sequence, it was designated a “retention motif.” During early development of the thylakoid system in chloroplasts, the site of assembly of LHCs is on a low-density membrane (inner envelope). These LHCs are functionally coupled to reaction centers within seconds after assembly.Subjects--Topical Terms:

1017825
Biology, Botany.

Assembly of light-harvesting complexes in Chlamydomonas reinhardtii.
LDR:03001nam 2200277 a 45 001 937579
005 20110511
008 110511s2003 eng d
035 $a (UnM)AAI3084616
035 $a AAI3084616
040 $a UnM $c UnM
100 1 $a Eggink, Laura Lynne. $3 1261441
245 1 0 $a Assembly of light-harvesting complexes in Chlamydomonas reinhardtii.
300 $a 99 p.
500 $a Adviser: J. Kenneth Hoober.
500 $a Source: Dissertation Abstracts International, Volume: 64-03, Section: B, page: 1038.
502 $a Thesis (Ph.D.)--Arizona State University, 2003.
520 $a Light-harvesting complexes (LHCs) are nuclear-encoded integral proteins in thylakoid membranes that collect and regulate delivery of exciton energy to photosynthetic reaction centers. Pigments, chlorophylls (Chl) <italic> a</italic> and <italic>b</italic> along with active xanthophylls, are required co-factors in assembly and function of LHCs. To investigate the <italic>in vivo</italic> site and mechanism of assembly of LHCs, the model organism, <italic> Chlamydomonas reinhardtii</italic>, was used for this study. Chl <italic> a</italic> and Chl <italic>b</italic> differ only in oxidation of the 7-methyl group of Chl <italic>a</italic> to a formyl group. Chlorophyll(ide) <italic> a</italic> oxygenase, the enzyme responsible for the oxidation, is membrane-associated and located on the inner envelope and thylakoid membranes, as shown by western blotting and immunoelectron microscopy. Conversion of the methyl group may be initiated by a radical, located on a conserved tyrosine, as shown by electron paramagnetic resonance. The ability of Chl <italic>b</italic> to form stronger coordination bonds with amino acid sidechains of the apoproteins of LHCs shifts equilibrium positions of complex formation toward assembly of LHCs in chloroplasts. In <italic>C. reinhardtii</italic>, Chl <italic>b</italic> is required for the import and retention of LHCs by the chloroplast. If Chl <italic> b</italic> is not available during import, assembly does not proceed and LHC apoproteins are shunted to cytoplasmic vacuoles. Molecular modeling of a highly conserved amino acid region within the apoprotein of LHCs, Glu-X-X-His/Asn-X-Arg, suggested that this motif may bind two molecules of Chl. The prediction was confirmed experimentally, which suggests that this motif may bind Chl during the import of LHCs. To indicate the importance of the sequence, it was designated a “retention motif.” During early development of the thylakoid system in chloroplasts, the site of assembly of LHCs is on a low-density membrane (inner envelope). These LHCs are functionally coupled to reaction centers within seconds after assembly.
590 $a School code: 0010.
650 4 $a Biology, Botany. $3 1017825
650 4 $a Biology, Cell. $3 1017686
650 4 $a Biology, Molecular. $3 1017719
690 $a 0307
690 $a 0309
690 $a 0379
710 2 0 $a Arizona State University. $3 1017445
773 0 $t Dissertation Abstracts International $g 64-03B.
790 $a 0010
790 1 0 $a Hoober, J. Kenneth, $e advisor
791 $a Ph.D.
792 $a 2003
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3084616