scholarly journals DNA Restriction and Modification in Escherichia coli: Functional Analysis of the Role of the dnaC(D) Gene Product

Microbiology ◽  
1980 ◽  
Vol 119 (1) ◽  
pp. 231-238
Author(s):  
J. HUBACEK ◽  
M. WEISEROVA
2001 ◽  
Vol 183 (9) ◽  
pp. 2817-2822 ◽  
Author(s):  
Melanie Blokesch ◽  
Axel Magalon ◽  
August Böck

ABSTRACT The hybG gene product from Escherichia colihas been identified as a chaperone-like protein acting in the maturation of hydrogenases 1 and 2. It was shown that HybG forms a complex with the precursor of the large subunit of hydrogenase 2. As with HypC, which is the chaperone-like protein involved in hydrogenase 3 maturation, the N-terminal cysteine residue is crucial for complex formation. Introduction of a deletion into hybG abolished the generation of active hydrogenase 2 but only quantitatively reduced hydrogenase 1 activity since HypC could replace HybG in this function. In contrast, HybG could not take over the role of HypC in a ΔhypC genetic background. Overproduction of HybG, especially of the variants with the replaced N-terminal cysteine residue, strongly interfered with hydrogenase 3 maturation, apparently by titrating some other component(s) of the maturation machinery. The results indicate that the three hydrogenase isoenzymes not only are interacting at the functional level but are also interconnected during the maturation process.


1968 ◽  
Vol 106 (2) ◽  
pp. 339-343 ◽  
Author(s):  
J. Palmer ◽  
V. Moses

1. The specific role of the lac repressor (i-gene product) in transient catabolite repression evoked by the introduction of glucose into the medium has been investigated in Escherichia coli by using mutants of the i-gene. 2. A temperature-sensitive mutant (iTL) is normally inducible and demonstrates transient repression when grown at 32°. At 42° it is about 20% constitutive and transient catabolite repression is abolished. 3. A strain carrying an amber suppressor-sensitive mutation in the i-gene is phenotypically constitutive and also fails to show transient catabolite repression. 4. Insertion of Flaci+ into this strain restores both inducibility and transient repression. 5. It is concluded that the i-gene product interacts with the catabolite co-repressor in such a way that its affinity for the operator is increased.


1979 ◽  
Vol 140 (2) ◽  
pp. 388-394 ◽  
Author(s):  
W D Donachie ◽  
K J Begg ◽  
J F Lutkenhaus ◽  
G P Salmond ◽  
E Martinez-Salas ◽  
...  

1997 ◽  
Vol 179 (14) ◽  
pp. 4583-4590 ◽  
Author(s):  
E Verderber ◽  
L J Lucast ◽  
J A Van Dehy ◽  
P Cozart ◽  
J B Etter ◽  
...  

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