scholarly journals CORRELATION OF BIOSYNTHESIS AND SHAPE-DETERMINING PROPERTIES OF THE PEPTIDOGLYCAN AND CELL DIVISION IN TEMPERATURE-SENSITIVE MUTANTS OF ESCHERICHIA COLI

1979 ◽  
Vol 25 (3) ◽  
pp. 149-160 ◽  
Author(s):  
GEORGE G. KHACHATOURIANS
1972 ◽  
Vol 20 (1) ◽  
pp. 65-74 ◽  
Author(s):  
H. J. W. Wijsman

SUMMARYSeveral temperature-sensitive mutants ofEscherichia coliwere isolated which lyse at the restrictive temperature. Some of these possess a biochemically defined lesion in cell-wall mucopeptide synthesis. Three genes, termedmurC, EandF, have been localized between theaziandleumarkers. From transductional data a fine structure map was constructed of themurmutations, establishing the order of the genes. The genetic relationship between these cell wall genes and neighbouring genes involved in cell division is discussed.


Genetics ◽  
1979 ◽  
Vol 91 (2) ◽  
pp. 215-227
Author(s):  
W Scott Champney

ABSTRACT Two variations of the method of localized mutagenesis were used to introduce mutations into the 72 min region of the Escherichia coli chromosome. Twenty temperature-sensitive mutants, with linkage to markers in this region, have been examined. Each strain showed an inhibition of growth in liquid medium at 44°, and 19 of the mutants lost viability upon prolonged incubation at this temperature. A reduction in the rate of in vivo RNA and protein synthesis was observed for each mutant at 44°, relative to a control strain. Eleven of the mutants were altered in growth sensitivity or resistance to one or more of three ribosomal antibiotics. The incomplete assembly of ribosomal subunits was detected in nine strains grown at 44°. The characteristics of these mutants suggest that many of them are altered in genes for translational or transcriptional components, consistent with the clustering of these genes at this chromosomal locus.


2019 ◽  
Vol 166 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Naoto Owada ◽  
Megumi Yoshida ◽  
Kohei Morita ◽  
Kenjiro Yoshimura

Abstract MscL is a mechanosensitive channel that undergoes a global conformational change upon application of membrane stretching. To elucidate how the structural stability and flexibility occur, we isolated temperature-sensitive (Ts) mutants of Escherichia coli MscL that allowed cell growth at 32°C but not at 42°C. Two Ts mutants, L86P and D127V, were identified. The L86P mutation occurred in the second transmembrane helix, TM2. Substitution of residues neighbouring L86 with proline also led to a Ts mutation, but the substitution of L86 with other amino acids did not result in a Ts phenotype, indicating that the Ts phenotype was due to a structural change of TM2 helix by the introduction of a proline residue. The D127V mutation was localized in the electrostatic belt of the bundle of cytoplasmic helices, indicating that stability of the pentameric bundle of the cytoplasmic helix affects MscL structure. Together, this study described a novel class of MscL mutations that were correlated with the thermodynamic stability of the MscL structure.


Author(s):  
T. Davies ◽  
S. Sundaramoorthy ◽  
S.N. Jordan ◽  
M. Shirasu-Hiza ◽  
J. Dumont ◽  
...  

1966 ◽  
Vol 41 (3) ◽  
pp. 247-249 ◽  
Author(s):  
YOSHINOBU SUGINO ◽  
AKIKO SORAI ◽  
TOKIO KOGOMA ◽  
YUKINORI HIROTA ◽  
REIJI OKAZAKI

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