| Autor: |
Firsova YE; Laboratory of Radioactive Isotopes, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, FRC Pushchino Center for Biological Research of Russian Academy of Sciences, Pushchino, Russia, 142290., Torgonskaya ML; Laboratory of Radioactive Isotopes, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, FRC Pushchino Center for Biological Research of Russian Academy of Sciences, Pushchino, Russia, 142290. torgonskaya@ibpm.ru. |
| Jazyk: |
angličtina |
| Zdroj: |
Antonie van Leeuwenhoek [Antonie Van Leeuwenhoek] 2020 Jan; Vol. 113 (1), pp. 101-116. Date of Electronic Publication: 2019 Aug 28. |
| DOI: |
10.1007/s10482-019-01320-5 |
| Abstrakt: |
The genome of methylotrophic bacteria Methylorubrum extorquens DM4 contains two homologous groESL operons encoding the 60-kDa and 10-kDa subunits of GroE heat shock chaperones with highly similar amino acid sequences. To test a possible functional redundancy of corresponding GroEL proteins we attempted to disrupt the groEL1 and groEL2 genes. Despite the large number of recombinants analysed and the gentle culture conditions the groEL1-lacking mutant was not constructed suggesting that the loss of GroEL1 was lethal for cells. At the same time the ∆groEL2 strain was viable and varied from the wild-type by increased sensitivity to acid, salt and desiccation stresses as well as by the impaired growth with a toxic halogenated compound-dichloromethane (DCM). The evaluation of activity of putative P groE1 and P groE2 promoters using the reporter gene of green fluorescent protein (GFP) showed that the expression of groESL1 operon greatly prevails (about two orders of magnitude) over those of groESL2 under all tested conditions. However the above promoters demonstrated differential regulation in response to stresses. The expression from P groE1 was heat-inducible, while the activity of P groE2 was upregulated upon acid shock and cultivation with DCM. Based on these results we conclude that the highly conservative groESL1 operon (old locus tags METDI5839-5840) encodes the housekeeping chaperone essential for fundamental cellular processes. On the contrary the second pair of paralogues (METDI4129-4130) is dispensable, but corresponding GroE2 chaperone promotes the tolerance to acid and salt stresses, in particular, during the growth with DCM. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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