Methionine starvation caused reprogrammed metabolism in Streptococcus pneumoniae

In our study, deletion of methionine synthesis gene metE (SPD_0510) impaired the growth of Streptococcus pneumoniae strain D39 significantly when bacteria were cultured in chemically defined medium with a low concentration of methionine. Bacteria undergo methionine starvation in this condition. We aimed to know how S. pneumoniae responses to methionine starvation, particularly at the transcriptional level. RNA-seq results show that 804 genes (41.2 % of whole genome) were differentially expressed under methionine starvation. Among them, 258 genes (32.1 %) are related to cell metabolism, with 75 genes involved in sugar and carbon metabolism, 88 genes for synthesis of metabolic products and 95 genes for uptake of amino acids and sugars. Combined with other experiments data, this showed the reprogrammed metabolism in S. pneumoniae under methionine starvation. Overall design: Transcriptome comparison of D39 WT and metEmutant in CDM with 1 µg/ml methionine. It was done by deep sequencing, using an Illumina instrument with 150 nt paired-end reads.