caa a22 4500 605497990 CHVBK 20210128100544.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00253-014-6067-y doi (NATIONALLICENCE)springer-10.1007/s00253-014-6067-y ClaR—a novel key regulator of cellobiose and lactose metabolism in Lactococcus lactis IL1403 [Elektronische Daten] [Tamara Aleksandrzak-Piekarczyk, Lidia Stasiak-Różańska, Jarosław Cieśla, Jacek Bardowski] 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. The Author(s), 2014 Lactoseassimilation nationallicence Cellobiose assimilation nationallicence Phosphotransferase system (PTS) nationallicence Genes regulation nationallicence Lactococcus lactis nationallicence Aleksandrzak-Piekarczyk Tamara Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106, Warsaw, Poland aut Stasiak-Różańska Lidia Department of Biotechnology, Microbiology and Food Evaluation, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-776, Warsaw, Poland aut Cieśla Jarosław Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106, Warsaw, Poland aut Bardowski Jacek Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106, Warsaw, Poland aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/1(2015-01-01), 337-347 0175-7598 99:1<337 2015 99 253 https://doi.org/10.1007/s00253-014-6067-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-014-6067-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Aleksandrzak-Piekarczyk Tamara Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106, Warsaw, Poland aut NATIONALLICENCE 700 1- Stasiak-Różańska Lidia Department of Biotechnology, Microbiology and Food Evaluation, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-776, Warsaw, Poland aut NATIONALLICENCE 700 1- Cieśla Jarosław Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106, Warsaw, Poland aut NATIONALLICENCE 700 1- Bardowski Jacek Institute of Biochemistry and Biophysics, Polish Academy of Sciences (IBB PAS), Pawińskiego 5a, 02-106, Warsaw, Poland aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/1(2015-01-01), 337-347 0175-7598 99:1<337 2015 99 253