scholarly journals Synthesis of mot and che gene products of Escherichia coli programmed by hybrid ColE1 plasmids in minicells.

1977 ◽  
Vol 132 (3) ◽  
pp. 996-1002 ◽  
Author(s):  
P Matsumura ◽  
M Silverman ◽  
M Simon
1984 ◽  
Vol 259 (3) ◽  
pp. 1807-1812 ◽  
Author(s):  
M Hanatani ◽  
H Yazyu ◽  
S Shiota-Niiya ◽  
Y Moriyama ◽  
H Kanazawa ◽  
...  

2000 ◽  
Vol 182 (17) ◽  
pp. 4862-4867 ◽  
Author(s):  
Marion Graupner ◽  
Huimin Xu ◽  
Robert H. White

ABSTRACT The products of two adjacent genes in the chromosome ofMethanococcus jannaschii are similar to the amino and carboxyl halves of phosphonopyruvate decarboxylase, the enzyme that catalyzes the second step of fosfomycin biosynthesis inStreptomyces wedmorensis. These two M. jannaschii genes were recombinantly expressed inEscherichia coli, and their gene products were tested for the ability to catalyze the decarboxylation of a series of α-ketoacids. Both subunits are required to form an α6β6 dodecamer that specifically catalyzes the decarboxylation of sulfopyruvic acid to sulfoacetaldehyde. This transformation is the fourth step in the biosynthesis of coenzyme M, a crucial cofactor in methanogenesis and aliphatic alkene metabolism. The M. jannaschiisulfopyruvate decarboxylase was found to be inactivated by oxygen and reactivated by reduction with dithionite. The two subunits, designated ComD and ComE, comprise the first enzyme for the biosynthesis of coenzyme M to be described.


Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 775-787 ◽  
Author(s):  
Hannes Nahrstedt ◽  
Christine Schröder ◽  
Friedhelm Meinhardt

Isolation and subsequent knockout of a recA-homologous gene in Bacillus megaterium DSM 319 resulted in a mutant displaying increased sensitivity to mitomycin C. However, this mutant did not exhibit UV hypersensitivity, a finding which eventually led to identification of a second functional recA gene. Evidence for recA duplicates was also obtained for two other B. megaterium strains. In agreement with potential DinR boxes located within their promoter regions, expression of both genes (recA1 and recA2) was found to be damage-inducible. Transcription from the recA2 promoter was significantly higher than that of recA1. Since a recA2 knockout could not be achieved, functional complementation studies were performed in Escherichia coli. Heterologous expression in a RecA null mutant resulted in increased survival after UV irradiation and mitomycin C treatment, proving both recA gene products to be functional in DNA repair. Thus, there is evidence for an SOS-like pathway in B. megaterium that differs from that of Bacillus subtilis.


1998 ◽  
Vol 180 (8) ◽  
pp. 2232-2236 ◽  
Author(s):  
Yoshizumi Ishino ◽  
Kayoko Komori ◽  
Isaac K. O. Cann ◽  
Yosuke Koga

ABSTRACT One of the most puzzling results from the complete genome sequence of the methanogenic archaeon Methanococcus jannaschii was that the organism may have only one DNA polymerase gene. This is because no other DNA polymerase-like open reading frames (ORFs) were found besides one ORF having the typical α-like DNA polymerase (family B). Recently, we identified the genes of DNA polymerase II (the second DNA polymerase) from the hyperthermophilic archaeonPyrococcus furiosus, which has also at least one α-like DNA polymerase (T. Uemori, Y. Sato, I. Kato, H. Doi, and Y. Ishino, Genes Cells 2:499–512, 1997). The genes in M. jannaschiiencoding the proteins that are homologous to the DNA polymerase II ofP. furiosus have been located and cloned. The gene products of M. jannaschii expressed in Escherichia colihad both DNA polymerizing and 3′→5′ exonuclease activities. We propose here a novel DNA polymerase family which is entirely different from other hitherto-described DNA polymerases.


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