Deoxyribonucleic Acid Distribution in Bacillus subtilis Independent of Cell Elongation

Self Cite

The growth and division properties of a temperature-sensitive mutant of Bacillus subtilis defective in the initiation of cell division have been studied. Log-phase cells transferred from 30 to 45 C continue to increase in length but fail to initiate new divisions. Deoxyribonucleic acid synthesis continues at 45 C, and genomes are segregated along the filament length. When filaments are returned to 30 C, division initiation resumes, and the long multinucleate clones are partitioned into normal-size cells. Occasionally, multiple cross walls initiate in close proximity, resulting in tiny cells, some of which are anucleate. Division resumption is sensitive to protein synthesis inhibitors, suggesting there is a new protein required for the initiation of division in filaments. Cell division has been studied in bacteria at the cellular level by several approaches (1, 5,

Section: Discussionsupporting

confidence: 63%

Genetic Regulation of Cell Division Initiation in Bacillus subtilis

Mendelson

Cole

1972

Self Cite

“…Surprisingly little is known about the structural organization of Bacillus subtilis cytoplasm, particularly with respect to unit cell amounts of components that are partitioned into daughter cells at cell division. Attention has focused on the distribution of daughter genomes during the cell cycle and to some degree upon the location of division sites along cell length (3,(7)(8)(9)(10). Other studies have been concerned with minimal cell sizes found in experimental populations (15).…”

mentioning

confidence: 99%

Cellular organization of Bacillus subtilis: sodium dodecyl sulfate-induced cell partitioning into zebra structures

Mendelson¹,

Haag²,

Cole³

1976

Cells ofBacillus subtilis heated in high concentrations of sodium dodecyl sulfate (5%) and then washed free of detergent with a hot salt solution (80 C) become structurally reorganized into regions of densely compacted cytoplasm (termed zebras) and regions of sparsely filled material (termed spaces). Size distribution studies of zebras indicate that division-suppressed mutants and wildtype cells both yield zebras of comparable length. Similarly the lengths of zebras found in populations emerging from spores are uniform in one-, two-, three-, and four-zebra-containing cells. In contrast, the length of spaces is slightly larger than that of zebras and is unusually large in two-zebra-containing cells. The locations of zebras and spaces along cell length have been studied in spore outgrowth populations. A statistical procedure developed previously in genome location investigations was used to analyze the location of zebras along cell length. The data indicate that as cells elongate, new sites arise where the cell contents are strongly bound to the cell surface. Within filament populations produced by division-suppressed mutants there is a linear relationship of mean filament length and zebra number per filament. These data indicate that cytoplasm in filaments with no obvious structural compartmentalizations may be organized into units associated with particular regions of cell surface. The attachment of cell contents to the cell surface may involve deoxyribonucleic acid. Zebra-containing cells digested with proteolytic enzyme and ribonuclease are converted to cells that contain a crystalline-like granule fixed at the location of each zebra. Exposure to deoxyribonuclease mobilizes these granules within the cell wall. also presented that indicates a role of deoxyribonucleic acid (DNA) in the attachment of cytoplasm to the cell surface.MATERIALS AND METHODS Bacteria. The following strains of B. subtilis 168 were used: CU403 thy-, met-, ilv-; CU403 div IV-B1, thy-, met-; CU403 divIV-B1, ts-134, thy-; CU403 divIV-A1, tms-12, thy-. The latter three 1285 on August 6, 2020 by guest

“…Using the transformation procedure of Bettinger and Young (2), the dna initiation mutant strain RB334 (trpC2 ts-151) was obtained as the product of the genetic cross: strain 168 (trpC2 pheA) (recipient) x strain 168 ts-151 (donor). B. subtilis strain 168 ts-151 was generously provided by Neil Mendelson (16). Transformants were selected at 30°C for the Phe+ phenotype and then screened for the ability to propagate at 45°C.…”

Section: Methodsmentioning

confidence: 99%

Altered accumulation of a membrane protein unique to a membrane-deoxyribonucleic acid complex in a dna initiation mutant of Bacillus subtilis

Harmon¹,

Taber²

1977

Membrane-deoxyribonucleic acid complexes (M-bands) have been isolated from Bacillus subtilis by their affinity for crystals of Mg2+-Sarkosyl. The membrane proteins of these complexes were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Comparison of the membrane protein composition of M-band and unfractionated membrane revealed three protein components of 125,000 (mac-1), 57,000 (mac-2), and 42,000 (mac-3) daltons unique to M-band membrane. Growth of a temperature-sensitive dna initiation mutant at the restrictive temperature resulted in an accumulation in the membrane of mac-2. This accumulation did not begin, however, until cell growth had nearly ceased, some 3 to 4 h after the cessation of deoxyribonucleic acid synthesis. Upon return of the mutant to the permissive temperature, mac-2 did not begin to return to normal levels until after the first round of deoxyribonucleic acid synthesis. A protein of 30,000 daltons, common to both M-band and whole membrane, was found to disappear from the membrane when the mutant was grown at the restrictive temperature. This disappearance is the result of increased degradation or removal from the membrane followed by a decreased rate of synthesis or insertion.