Chromosome segregation in Streptococcus pneumoniae

Segregation of replicated chromosomes during cell division is an essential process in all organisms. Chromosome segregation is promoted by the action of the DNA-binding ParB protein in the rod-shaped model bacterium Bacillus subtilis. How oval shaped bacteria, such as the human pathogen Streptococcus pneumoniae, efficiently segregate their chromosomes is poorly understood. Here, we show that the pneumococcal homolog of ParB is enriched at four centromere-like DNA sequences (parS sites) that are present near the origin of replication. Amplified ChIP DNA was fluorescently labelled using the BioPrime Total Genomic Labeling kit from Invitrogen. Eluate DNA was labelled with AlexA Fluor 3 and input DNA with Alexa Fluor 5. Labelled DNA was hybridized to a DNA-microarray containing amplicons of all open reading frames of S. pneumoniae (Kloosterman et al., 2006).