J Mol Microbiol Biotechnol. 2015 Nov 7;25(6):363-371. [Epub ahead of print]

GalR Acts as a Transcriptional Activator of galKT in the Presence of Galactose inStreptococcus pneumoniae.

Afzal M1, Shafeeq S, Manzoor I, Kuipers OP.

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We explored the regulatory mechanism of Leloir pathway genes in Streptococcus pneumoniae D39. Here, we demonstrate that the expression of galKT is galactose dependent. By microarray analysis and quantitative RT-PCR, we further show the role of the transcriptional regulator GalR, present upstream of galKT, as a transcriptional activator of galKT in the presence of galactose. Moreover, we predict a 19-bp regulatory site (5'-GATAGTTTAGTAAAATTTT-3') for the transcriptional regulator GalR in the promoter region of galK, which is also highly conserved in other streptococci. Growth comparison of D39 x0394;galK with the D39 wild type grown in the presence of galactose shows that galK is required for the proper growth of S. pneumoniae on galactose.

© 2015 S. Karger AG, Basel.

PMID: 26544195