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BUDOWA I EKSPRESJA OPERONÓW KATABOLICZNYCH
DEGRADACJI FENOLU U BAKTERII
Joanna Nowak*
Laboratorium Mikrobiologii Reckitt Benckiser Production (Poland) Sp. z o.o.
ul. Sikorkiego 1/31, 05-101 Nowy Dwór Mazowiecki
Wpłynęło w kwietniu 2007 r.
1. Wstęp. 2. Hydroksylazy fenolowe. 3. Genetyczna organizacja operonów katabolicznych degradcji fenolu. 4. Kontrola ekspresji operonów katabolizmu fenolu - białka regulatorowe. 4.1. Regulatory typu XylR/DmpR. 4.2. Regulatory typu GntR. 4.3. Regulatory typu AraC/XylS. 4.4. Regulatory typu LysR. 5. Podsumowanie
Structure and expression of catabolic operons for phenol degradation in bacteria
Abstract: Phenol is a common environmental pollutant discharged from such industrial facilities as oil refineries and chemical plants. The initial step of aerobic degradation of phenol is catalyzed by phenol hydroxylase that incorporates one oxygen atom of molecular oxygen into the aromatic ring to form catechol. The second step is catalyzed by catechol 1,2-dioxygenase (ortho fission) or catechol 2,3-dioxygenase (meta fission). The initial hydroxylation is considered to be the rate-limiting step in the degradative pathway. To date, two types of bacterial phenol hydroxylases, single-component and multi-component type, have been identified.
Phenol degradative enzymes are coded in operons which are located on the chromosome or plasmids. The expression of phenol degradative genes is controlled by one or more regulatory proteins. These proteins belong to four different families of transcriptional regulators: LysR, XylR/DmpR, AraC/XylS and GntR.
Operons for phenol degradation can be adapted to create bacterial biosensors for the detection of industrial pollution. The understanding of regulatory mechanisms which govern the expression of the phenol catabolic pathway might be an important challenge in the application of bacterial regulatory systems in bioremediation and in the creation of bacterial biosensors for measuring the quality of soil and water.
1. Introduction. 2. Phenol hydroxylases. 3. Genetic organization of catabolic operons for phenol degradation. 4. Control of expression of operons for phenol catabolizm - regulatory proteins. 4.1. XylR/DmpR family of regulatory proteins. 4.2. GntR family of regulatory proteins. 4.3. AraC/XylS family of regulatory proteins. 4.4. LysR family of regulatory proteins. 5. Summary
Słowa kluczowe: białka regulatorowe, degradacja, hydroksylazy fenolowe,
operony
Key words: regulatory proteins, degradation, phenol hydroxylase, operons
* Autor do korespondencji: Laboratorium Mikrobiologii Reckitt Benckiser Production (Poland) Sp. z o.o. ul. Sikorkiego 1/31, 05-101 Nowy Dwór Mazowiecki; joanna_nowak@o2.pl
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