Rod substructure in cyanobacterial phycobilisomes: analysis of Synechocystis 6701 mutants low in phycoerythrin.

Content Provider	Scilit
Author	Gingrich, Jeffrey C. Blaha, Lauren K. Glazer, Alexander N.
Copyright Year	1982
Description	Synechocystis 6701 phycobilisomes contain phycoerythrin, phycocyanin, and allophycocyanin in a molar ratio of approximately 2:2:1, and other polypeptides of 99-, 46-, 33.5-, 31.5-, 30.5-, and 27-kdaltons. Wild-type phycobilisomes consist of a core of three cylindrical elements in an equilateral array surrounded by a fanlike array of six rods each made up of 3-4 stacked disks. Twelve nitrosoguanidine-induced mutants were isolated which produced phycobilisomes containing between 0 and 53% of the wild-type level of phycoerythrin and grossly altered levels of the 30.5- and 31.5-kdalton polypeptides. Assembly defects in these mutant particles were shown to be limited to the phycoerythrin portions of the rod substructures of the phycobilisome. Quantitative analysis of phycobilisomes from wild-type and mutant cells, grown either in white light or chromatically adapted to red light, indicated a molar ratio of the 30.5- and 31.5-kdalton polypeptides to phycoerythrin of 1:6, i.e., one 30.5- or one 31.5-kdaltons polypeptide per (alpha beta)6 phycoerythrin hexamer. Presence of the phycoerythrin-31.5-kdalton complex in phycobilisomes did not require the presence of the 30.5-kdalton polypeptide. The converse situation was not observed. These and earlier studies (R. C. Williams, J. C. Gingrich, and A. N. Glazer. 1980. J. Cell Biol. 85:558-566) show that the average rod in wild type Synechocystis 6701 phycobilisomes consists of four stacked disk-shaped complexes: phycocyanin (alpha beta)6-27 kdalton, phycocyanin (alpha beta)6-33.5 kdalton, phycoerythrin (alpha beta)6-31.5 kdalton, and phycoerythrin-30.5 kdalton, listed in order starting with the disk proximal to the core.
Related Links	http://jcb.rupress.org/content/92/2/261.full.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2112072/pdf
Ending Page	268
Page Count	8
Starting Page	261
DOI	10.1083/jcb.92.2.261
Journal	Journal of Cell Biology
Issue Number	2
Volume Number	92
Language	English
Publisher	Rockefeller University Press
Publisher Date	1982-02-01
Access Restriction	Open
Subject Keyword	Biochemistry and Molecular Biology Quantitative Analysis Wild Type Journal: Journal of Cell Biology (Vol- 92, Issue- 2)
Content Type	Text