Sialic acid-mediated gene expression in Streptococcus pneumoniae and role of NanR as a transcriptional activator of the nan gene cluster.

Abstract

In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to sialic acid (N-acetylneuraminic acid [Neu5Ac]). Transcriptome comparison of wild-type D39 grown in M17 medium with and without sialic acid revealed the elevated expression of various genes and operons, including the nan gene cluster (nan operon I and nanA gene). Our microarray analysis and promoter-lacZ fusion studies showed that the transcriptional regulator NanR acts as a transcriptional activator of nan operon I and the nanA gene in the presence of sialic acid. The putative regulatory site of NanR in the promoter region of nan operon I is predicted and confirmed by promoter truncation experiments. Furthermore, the role of CcpA in the regulation of the nan gene cluster is demonstrated through microarray analysis and promoter-lacZ fusion studies, suggesting that in the presence of sialic acid and glucose, CcpA represses the expression of nan operon I while the expression of the nanA gene is CcpA independent.

DOI: 10.1128/AEM.00499-15

Cite this paper

@article{Afzal2015SialicAG, title={Sialic acid-mediated gene expression in Streptococcus pneumoniae and role of NanR as a transcriptional activator of the nan gene cluster.}, author={Muhammad Haris Afzal and Sulman Shafeeq and Hifza Ahmed and Oscar P. Kuipers}, journal={Applied and environmental microbiology}, year={2015}, volume={81 9}, pages={3121-31} }