Leucine responsive regulatory protein is involved in methionine metabolism and polyamine homeostasis in acetic acid bacterium Komagataeibacter europaeus.
J Biosci Bioeng
; 125(1): 67-75, 2018 Jan.
Article
in En
| MEDLINE
| ID: mdl-28867618
ABSTRACT
The leucine responsive regulatory protein (Lrp) is a global transcription factor that regulates the expression of genes involved in amino acid metabolism. To identify metabolic pathways and related genes under the control of Lrp in the acetic acid bacterium Komagataeibacter europaeus, the Kelrp null mutant (KGMA7110), which requires supplementation of all 20 amino acids for normal growth, was cultivated in minimal media containing or lacking particular amino acids. The results confirmed that KGMA7110 was auxotrophic for methionine and its catabolites S-adenosylmethionine (SAM) and spermidine (SPD). Quantitative reverse-transcription PCR analysis revealed lower metK (SAM synthetase) and mdtI (SPD efflux pump) expression in KGMA7110 than in wild-type KGMA0119. By contrast, these genes were significantly up-regulated in the Kelrp mutant lacking the putative C-terminal ligand-sensing domain (KGMA7203), indicating abnormal regulation of target genes by the KeLrp variant in KGMA7203. KGMA7110 (0.69±0.27 µM) and KGMA7203 (4.90±0.61 µM) excreted lower and higher quantities of SPD, respectively, than KGMA0119 (2.28±0.26 µM). This was attributed to imbalanced carbon flow caused by Kelrp disruption that respectively attenuated and stimulated metK and mdtI expression. These findings indicate that KeLrp plays a key role in SAM biosynthesis and intracellular polyamine homeostasis in K. europaeus.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polyamines
/
Acetic Acid
/
Gluconacetobacter
/
Leucine-Responsive Regulatory Protein
/
Homeostasis
/
Methionine
Type of study:
Prognostic_studies
Language:
En
Journal:
J Biosci Bioeng
Journal subject:
ENGENHARIA BIOMEDICA
/
MICROBIOLOGIA
Year:
2018
Document type:
Article
Affiliation country:
Japan