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Deacetylation of topoisomerase I is an important physiological function of E. coli CobB
- Source :
- Nucleic Acids Research
- Publication Year :
- 2017
- Publisher :
- Oxford University Press (OUP), 2017.
-
Abstract
- Escherichia coli topoisomerase I (TopA), a regulator of global and local DNA supercoiling, is modified by Nε-Lysine acetylation. The NAD+-dependent protein deacetylase CobB can reverse both enzymatic and non-enzymatic lysine acetylation modification in E. coli. Here, we show that the absence of CobB in a ΔcobB mutant reduces intracellular TopA catalytic activity and increases negative DNA supercoiling. TopA expression level is elevated as topA transcription responds to the increased negative supercoiling. The slow growth phenotype of the ΔcobB mutant can be partially compensated by further increase of intracellular TopA level via overexpression of recombinant TopA. The relaxation activity of purified TopA is decreased by in vitro non-enzymatic acetyl phosphate mediated lysine acetylation, and the presence of purified CobB protects TopA from inactivation by such non-enzymatic acetylation. The specific activity of TopA expressed from His-tagged fusion construct in the chromosome is inversely proportional to the degree of in vivo lysine acetylation during growth transition and growth arrest. These findings demonstrate that E. coli TopA catalytic activity can be modulated by lysine acetylation–deacetylation, and prevention of TopA inactivation from excess lysine acetylation and consequent increase in negative DNA supercoiling is an important physiological function of the CobB protein deacetylase.
- Subjects :
- DNA, Bacterial
Proteomics
0301 basic medicine
030106 microbiology
Mutant
Lysine
Biology
medicine.disease_cause
complex mixtures
03 medical and health sciences
chemistry.chemical_compound
Escherichia coli
Genetics
medicine
Sirtuins
Electrophoresis, Agar Gel
DNA, Superhelical
Nucleic Acid Enzymes
Escherichia coli Proteins
Acetylation
Chromosomes, Bacterial
Recombinant Proteins
Phenotype
DNA Topoisomerases, Type I
Solubility
chemistry
Biochemistry
Mutation
Biocatalysis
bacteria
DNA supercoil
Protein deacetylase
NAD+ kinase
DNA
Protein Binding
Subjects
Details
- ISSN :
- 13624962 and 03051048
- Volume :
- 45
- Database :
- OpenAIRE
- Journal :
- Nucleic Acids Research
- Accession number :
- edsair.doi.dedup.....e119eef13b9d87fa0552fde928068301