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ClaR—a novel key regulator of cellobiose and lactose metabolism in Lactococcus lactis IL1403

Aleksandrzak-Piekarczyk, Tamara and Stasiak-Różanska, Lidia and Cieśla, Jarosław M. and Bardowski, Jacek K. (2015) ClaR—a novel key regulator of cellobiose and lactose metabolism in Lactococcus lactis IL1403. Applied Microbiology and Biotechnology, 99 . pp. 337-347. ISSN 0175-7598

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Official URL: http://link.springer.com/article/10.1007%2Fs00253-...


In a number of previous studies, our group has discovered an alternative pathway for lactose utilization in Lactococcus lactis that, in addition to a sugar-hydrolyzing enzyme with both P-β-glucosidase and P-β-galactosidase activity (BglS), engages chromosomally encoded components of cellobiose-specific PTS (PTSCel-Lac), including PtcA, PtcB, and CelB. In this report, we show that this system undergoes regulation via ClaR, a novel activator protein from the RpiR family of transcriptional regulators. Although RpiR proteins are widely distributed among lactic acid bacteria, their roles have yet to be confirmed by functional assays. Here, we show that ClaR activity depends on intracellular cellobiose-6-phosphate availability, while other sugars such as glucose or galactose have no influence on it. We also show that ClaR is crucial for activation of the bglS and celB expression in the presence of cellobiose, with some limited effects on ptcA and ptcB activation. Among 190 of carbon sources tested, the deletion of claR reduces L. lactis growth only in lactose- and/or cellobiose-containing media, suggesting a narrow specificity of this regulator within the context of sugar metabolism.

Item Type:Article
Subjects:Q Science > QR Microbiology
Divisions:Department of Microbial Biochemistry
ID Code:747
Deposited By: dr Tamara Aleksandrzak-Piekarczyk
Deposited On:24 Oct 2014 13:59
Last Modified:08 Mar 2018 15:33

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