title: Cysteine-Mediated Gene Expression and Characterization of the CmbR Regulon inStreptococcus pneumoniae.
abstract: In this study, we investigated the transcriptomic response ofStreptococcus pneumoniaeD39 to cysteine. Transcriptome comparison of the D39 wild-type grown at a restricted concentration of cysteine (0.03 mM) to one grown at a high concentration of cysteine (50 mM) in chemically-defined medium (CDM) revealed elevated expression of various genes/operons, i.e.,spd-0150,metQ,spd-0431,metEF,gshT,spd-0618,fhs, tcyB,metB-csd,metA,spd-1898,yvdE, andcysK, likely to be involved in the transport and utilization of cysteine and/or methionine. Microarray-based data were further confirmed by quantitative RT-PCR. PromoterlacZ-fusion studies and quantitative RT-PCR data showed that the transcriptional regulator CmbR acts as a transcriptional repressor ofspd-0150,metEF,gshT,spd-0618,tcyB,metA, andyvdE, putatively involved in cysteine uptake and utilization. The operator site of CmbR in the promoter regions of CmbR-regulated genes is predicted and confirmed by mutating or deleting CmbR operator sites from the promoter regions of these genes.
authors.affiliation: Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands; Department of Bioinformatics and Biotechnology, Government College UniversityFaisalabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Afzal
authors.affiliation: Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands; Department of Bioinformatics and Biotechnology, Government College UniversityFaisalabad, Pakistan.
authors.forename: Irfan
authors.initials: I
authors.lastname: Manzoor
authors.affiliation: Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands.
authors.forename: Oscar P
authors.initials: OP
authors.lastname: Kuipers
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet Stockholm, Sweden.
authors.forename: Sulman
authors.initials: S
authors.lastname: Shafeeq
keywords: CmbR; Cysteine; MetA; MetE; pneumococcus