Mapping the MinE Site Involved in Interaction with the MinD Division Site Selection Protein of Escherichia coli

Abstract

Interactions between the MinD and MinE proteins are required for proper placement of the Escherichia coli division septum. The site within MinE that is required for interaction with MinD was mapped by studying the effects of site-directed minE mutations on MinD-MinE interactions in yeast two-hybrid and three-hybrid experiments. This confirmed that the MinE N-terminal domain is responsible for the interaction of MinE with MinD. Mutations that interfered with the interaction defined an extended surface on one face of the ␣-helical region of the MinE N-terminal domain, consistent with the idea that the MinE-MinD interaction involves formation of a coiled-coil structure by interaction with a complementary helical surface within MinD.

Modeling Three-Dimensional Spatial Regulation of Bacterial Cell Division (Dissertation)

“…Therefore, because the polar zone still appeared, the ATPase activation function in the MinE N-terminal domain is likely at a very low basal level when the C-terminal domain is disrupted. Thirdly, the truncated N-terminal domain, which forms a nascent helix (King et al, 1999), can autonomously bind to the membrane in the absence of MinD (Ma et al, 2003), and in the full length MinE, the binding domain is thought to be exposed upon membrane recruitment by MinD (Ma et al, 2003). This further supports our theory that MinE constituting the E-ring remained transiently attached to the membrane independently after recruited by MinD.…”

“…This implies that the MinD ATPase activity is substantially reduced (Huang et al, 2003) in the absence of E-ring as a consequence of the disrupted MinE C-terminal domain. Strikingly, the MinD interaction domain resides near the MinE N-terminal (Ma et al, 2003), which was present. Therefore, because the polar zone still appeared, the ATPase activation function in the MinE N-terminal domain is likely at a very low basal level when the C-terminal domain is disrupted.…”

“…In addition, the width of the observed E-ring, which appears to be several times the length of a MinE dimer, is also unlikely to be the direct result of MinE dimers binding to MinD subunits at the rim. Truncated MinE N-terminal domain can autonomously bind to the membrane in the absence of MinD, and in the full length MinE, the binding domain is thought to be exposed upon membrane recruitment by MinD (Ma et al, 2003).…”

Towards understanding the molecular basis of bacterial DNA segregation

“…It is not known how MinE stimulates MinD or how Spo0J stimulates Soj, but the interaction determinants of MinE and Spo0J have both been mapped to the N-terminal 22 and 20 amino acids, respectively (Leonard et al 2004;Ma et al 2003). Furthermore, Leonard et al (2004) show that the activating regions of Spo0J and MinE contain significant sequence homology, including a conserved basic residue (see also Hu & Lutkenhaus 2001), mutation of which in Spo0J abrogates activation of Soj ATPase.…”

Modeling Three-Dimensional Spatial Regulation of Bacterial Cell Division (Dissertation)

“…First, since MinE cannot independently associate to the membrane, the putative membrane binding domain near the MinE Nterminal is only exposed upon binding with MinD on the membrane as suggested by Ma et al (2003). Second, we predict that MinE can only begin to transiently attach to the membrane independently of MinD when it is in the dimer form with the membrane binding domains at both N-terminals exposed.…”