Mini-F protein that binds to a unique region for partition of mini-F plasmid DNA

Abstract

A mini-F-coded protein, named F2 protein, binds specifically to mini-F DNA. This protein has a molecular weight of 37,000 and is coded by the A2 segment of the mini-F genome (47.3 to 49.4 kilobases on the F coordinate map). The binding site is located also in the A2 segment of mini-F. This binding site is lost by spontaneous deletion when the A2 segment alone, but not A2 together with its neighboring segment, is cloned in a multicopy plasmid pBR322. These data are discussed in connection with incompatibility and plasmid stability.