The ttpC gene is contained in two of three TonB systems in the human pathogen Vibrio vulnificus, but only one is active in iron transport and virulence.

The TonB system of proteins is required for the energy-dependent active transport of iron-bound substrates across the outer membrane of gram-negative bacteria. We have identified three TonB systems within the human pathogen Vibrio vulnificus. The TonB1 system contains the TonB1, ExbD1, and ExbB1 proteins, whereas both the TtpC2-TonB2 and TtpC3-TonB3 systems contain an additional fourth protein, TtpC.

Power plays: iron transport and energy transduction in pathogenic vibrios.

The Vibrios are a unique group of bacteria inhabiting a vast array of aquatic environments. Many Vibrio species are capable of infecting a wide assortment of hosts. Some of these species include V.

Surface sensing in Vibrio parahaemolyticus triggers a programme of gene expression that promotes colonization and virulence.

Vibrio parahaemolyticus senses surfaces via impeded rotation of its polar flagellum. We have exploited this surface-sensing mechanism to trick the organism into thinking it is on a surface when it is growing in liquid. This facilitated studies of global gene expression in a way that avoided many of the complications of surface-to-liquid comparisons, and illuminated ∼ 70 genes that respond to surface sensing per se.

ATP-binding site lesions in FtsE impair cell division.

FtsE and FtsX of Escherichia coli constitute an apparent ABC transporter that localizes to the septal ring. In the absence of FtsEX, cells divide poorly and several membrane proteins essential for cell division are largely absent from the septal ring, including FtsK, FtsQ, FtsI, and FtsN. These observations, together with the fact that ftsE and ftsX are cotranscribed with ftsY, which helps to target some proteins for insertion into the cytoplasmic membrane, suggested that FtsEX might contribute to insertion of division proteins into the membrane.

A predicted ABC transporter, FtsEX, is needed for cell division in Escherichia coli.

FtsE and FtsX have homology to the ABC transporter superfamily of proteins and appear to be widely conserved among bacteria. Early work implicated FtsEX in cell division in Escherichia coli, but this was subsequently challenged, in part because the division defects in ftsEX mutants are often salt remedial. Strain RG60 has an ftsE::kan null mutation that is polar onto ftsX.