Induction of the photosynthetic membranes of Rhodopseudomonas sphaeroides: biochemical and morphological studies
Cells of Rhodopseudomonas sphaeroides grown in a 25% O/sub 2/ atmosphere were rapidly subjected to total anaerobiosis in the presence of light to study the progression of events associated with the de novo synthesis of the inducible intracytoplasmic membrane (ICM). This abrupt change in physiological conditions resulted in the immediate cessation of cell growth and whole cell protein, DNBA, and phospholipid accumulation. Detectable cell growth and whole cell protein accumulation resumed ca. 12 h later. Bulk phospholipid accumulation paralleled cell growth, but the synthesis of individual phospholipid species during the adaptation period suggested the existence of a specific regulatory site in phospholipid synthesis at the level of the phosphatidylethanolamine methyltransferase system. Freeze-fracture electron microscopy showed that aerobic cells contain small indentations within the cell membrane that appear to be converted into discrete ICM invaginations within 1 hr after the imposition of anaerobiosis. Microscopic examination also revealed a series of morphological changes in ICM structure and organization during the lag period before the initiation of photosynthetic growth. Bacteriochlorophyll synthesis and the formation of the two light-harvesting bacteriochlorophyll-protein complexes of R. sphaeroides (B800-B875) occurred coordinately within 2 h after the shift to anaerobic conditions. Using antibodies prepared against various ICM-specific polypeptides, the synthesis of reaction center proteins and the polypeptides associated with the B800-850 complex was monitored. The reaction center H polypeptide was immunochemically detected at low levels in the cell membrane of aerobic cells, which contained no detectable ICM or bacteriochlorophyll. 68 references, 11 figures.
- Research Organization:
- Univ. of Illinois, Urbana-Champaign
- OSTI ID:
- 5930892
- Journal Information:
- J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 159:2; ISSN JOBAA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOCHEMISTRY
BIOLOGICAL ADAPTATION
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL DIFFERENTIATION
CELL MEMBRANES
CHEMISTRY
CHLOROPHYLL
DNA
ELECTROMAGNETIC RADIATION
ELEMENTS
ENZYMES
GROWTH
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
MEMBRANES
MICROORGANISMS
MORPHOLOGICAL CHANGES
MORPHOLOGY
NONMETALS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN
PHOTOSYNTHETIC MEMBRANES
PHOTOSYNTHETIC REACTION CENTERS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
RADIATIONS
RHODOPSEUDOMONAS
TRANSFERASES
VISIBLE RADIATION