title: Characterization of DicB by partially masking its potent inhibitory activity of cell division.
abstract: DicB, a protein encoded by the Kim (Qin) prophage in Escherichia coli, inhibits cell division through interaction with MinC. Thus far, characterization of DicB has been severely hampered owing to its potent activity which ceases cell division and leads to cell death. In this work, through fusing maltose-binding protein to the N-terminus of DicB (MBP-DicB), we successfully expressed and purified recombinant DicB that enabled in vitro analysis for the first time. More importantly, taking advantage of the reduced inhibitory activity of MBP-DicB, we were able to study its effects on cell growth and morphology. Inhibition of cell growth by MBP-DicB was systematically evaluated using various DicB constructs, and their corresponding effects on cell morphology were also investigated. Our results revealed that the N-terminal segment of DicB plays an essential functional role, in contrast to its C-terminal tail. The N-terminus of DicB is of critical importance as even the first amino acid (following the initial Met) could not be removed, although it could be mutated. This study provides the first glimpse of the molecular determinants underlying DicB's function.
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China.
authors.forename: Shaoyuan
authors.initials: S
authors.lastname: Yang
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China.
authors.forename: Hairun
authors.initials: H
authors.lastname: Pei
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wei
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhu
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China jimin_z@bnu.edu.cn.
authors.forename: Jimin
authors.initials: J
authors.lastname: Zheng
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China Department of Biomedical and Molecular Sciences, Queen's University, Ontario, Canada K7L 3N6 jia@queensu.ca.
authors.forename: Zongchao
authors.initials: Z
authors.lastname: Jia
mesh_terms: D002455:Cell Division; D004926:Escherichia coli / Q000254:growth & development* / Q000821:virology; D015964:Gene Expression Regulation, Bacterial; D008320:Maltose / Q000378:metabolism; D039002:Prophages / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D008320:Maltose
keywords: DicB; MBP; MinC; cell division inhibition; prophage