1.Identification of transmembrane helix 1 (TM1) surfaces important for EnvZ dimerisation and signal output.
Heininger A1, Yusuf R2, Lawrence RJ3, Draheim RR4. Biochim Biophys Acta. 2016 May 4. pii: S0005-2736(16)30144-4. doi: 10.1016/j.bbamem.2016.05.002. [Epub ahead of print]
The Escherichia coli sensor kinase EnvZ modulates porin expression in response to various stimuli, including extracellular osmolarity, the presence of procaine and interaction with an accessory protein, MzrA. Two major outer membrane porins, OmpF and OmpC, act as passive diffusion-limited pores that allow compounds, including certain classes of antibiotics such as β-lactams and fluoroquinolones, to enter the bacterial cell. Even though the mechanisms by which EnvZ detects and processes the presence of various stimuli are a fundamental component of microbial physiology, they are not yet fully understood. Here, we assess the role of TM1 during signal transduction in response to the presence of extracellular osmolarity. Various mechanisms of transmembrane communication have been proposed including rotation of individual helices within the transmembrane domain, dynamic movement of the membrane-distal portion of the cytoplasmic domain and regulated intra-protein unfolding.
