Fig 6.

Centromere activity assay of segS elements using a plasmid stability test in Escherichia coli. (A and B) The segS1 (S1), segS2 (S2), and segS3 (S3) elements were cloned into unstable mini-F plasmid pDAG203 (V), and cells carrying recombinant plasmids pDAGS1, pDAGS2, and pDAGS3 and pDAGS3-harboring cells coexpressing either ParB1 (S3+B1) or ParB1 and ParA1 together (S3+A1B1) (B) were checked for plasmid stability as a function of chloramphenicol resistance (A). Data were compared with data for cells carrying vector pDAG203 (V) alone and also coexpressing both ParA1 and ParB1 in the vector background (V+A1B1) (B). (C and D) Genomic DNAs prepared from 5 independent clones (clones 1 to 5) of E. coli each harboring pDAGS1, pDAGS2, pDAGS3, and pDAG203 (pDAG) and relative proportions of plasmid (cat) and genomic (xerC) DNAs were checked for each clone (C), and the ratios of cat to xerC were calculated (D).