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Physiological function of the maltose operon regulator, MalR, in Lactococcus lactis.

Andersson, Ulrika LU and Rådström, Peter LU (2002) In BMC Microbiology 2.
Abstract
BACKGROUND: Maltose metabolism is initiated by an ATP-dependent permease system in Lactococcus lactis. The subsequent degradation of intracellular maltose is performed by the concerted action of Pi-dependent maltose phosphorylase and beta-phosphoglucomutase. In some Gram-positive bacteria, maltose metabolism is regulated by a maltose operon regulator (MalR), belonging to the LacI-GalR family of transcriptional regulators. A gene presumed to encode MalR has been found directly downstream the maltose phosphorylase-encoding gene, malP in L. lactis. The purpose of this study was to investigate the physiological role of the MalR protein in maltose metabolism in L. lactis. RESULTS: A L. lactis ssp. lactis mutant, TMB5004, deficient in the... (More)
BACKGROUND: Maltose metabolism is initiated by an ATP-dependent permease system in Lactococcus lactis. The subsequent degradation of intracellular maltose is performed by the concerted action of Pi-dependent maltose phosphorylase and beta-phosphoglucomutase. In some Gram-positive bacteria, maltose metabolism is regulated by a maltose operon regulator (MalR), belonging to the LacI-GalR family of transcriptional regulators. A gene presumed to encode MalR has been found directly downstream the maltose phosphorylase-encoding gene, malP in L. lactis. The purpose of this study was to investigate the physiological role of the MalR protein in maltose metabolism in L. lactis. RESULTS: A L. lactis ssp. lactis mutant, TMB5004, deficient in the putative MalR protein, was physiologically characterised. The mutant was not able to ferment maltose, while its capability to grow on glucose as well as trehalose was not affected. The activity of maltose phosphorylase and beta-phosphoglucomutase was not affected in the mutant. However, the specific maltose uptake rate in the wild type was, at its lowest, five times higher than in the mutant. This difference in maltose uptake increased as the maltose concentration in the assay was increased. CONCLUSION: According to amino acid sequence similarities, the presumed MalR is a member of the LacI-GalR family of transcriptional regulators. Due to the suggested activating effect on maltose transport and absence of effect on the activities of maltose phosphorylase and beta-phosphoglucomutase, MalR of L. lactis is considered rather as an activator than a repressor. (Less)
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published
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in
BMC Microbiology
volume
2
publisher
BioMed Central
external identifiers
  • scopus:0037174587
ISSN
1471-2180
language
English
LU publication?
yes
id
dd4c9b35-04fc-47e1-ad6d-18a1747f470e (old id 931171)
alternative location
http://www.biomedcentral.com/1471-2180/2/28
date added to LUP
2008-01-17 17:12:53
date last changed
2017-10-22 04:33:24
@article{dd4c9b35-04fc-47e1-ad6d-18a1747f470e,
  abstract     = {BACKGROUND: Maltose metabolism is initiated by an ATP-dependent permease system in Lactococcus lactis. The subsequent degradation of intracellular maltose is performed by the concerted action of Pi-dependent maltose phosphorylase and beta-phosphoglucomutase. In some Gram-positive bacteria, maltose metabolism is regulated by a maltose operon regulator (MalR), belonging to the LacI-GalR family of transcriptional regulators. A gene presumed to encode MalR has been found directly downstream the maltose phosphorylase-encoding gene, malP in L. lactis. The purpose of this study was to investigate the physiological role of the MalR protein in maltose metabolism in L. lactis. RESULTS: A L. lactis ssp. lactis mutant, TMB5004, deficient in the putative MalR protein, was physiologically characterised. The mutant was not able to ferment maltose, while its capability to grow on glucose as well as trehalose was not affected. The activity of maltose phosphorylase and beta-phosphoglucomutase was not affected in the mutant. However, the specific maltose uptake rate in the wild type was, at its lowest, five times higher than in the mutant. This difference in maltose uptake increased as the maltose concentration in the assay was increased. CONCLUSION: According to amino acid sequence similarities, the presumed MalR is a member of the LacI-GalR family of transcriptional regulators. Due to the suggested activating effect on maltose transport and absence of effect on the activities of maltose phosphorylase and beta-phosphoglucomutase, MalR of L. lactis is considered rather as an activator than a repressor.},
  author       = {Andersson, Ulrika and Rådström, Peter},
  issn         = {1471-2180},
  language     = {eng},
  publisher    = {BioMed Central},
  series       = {BMC Microbiology},
  title        = {Physiological function of the maltose operon regulator, MalR, in Lactococcus lactis.},
  volume       = {2},
  year         = {2002},
}