Anna R Greenswag's scientific contributions

Publications (5)

Article
Full-text available
During bacterial chemotaxis, transmembrane chemoreceptor arrays regulate autophosphorylation of the dimeric, histidine-kinase CheA. The five domains of CheA (P1-P5) each play a specific role in coupling receptor stimulation to CheA activity. Biochemical and x-ray scattering studies of thermostable CheA from Thermotoga maritima find that the His-con...
Article
Bacterial chemoreceptors associate with the histidine kinase CheA and coupling protein CheW into extended membrane arrays that receive and transduce environmental signals. A receptor trimer-of-dimers resides at each vertex of the hexagonal lattice of proteins that comprises the array. CheA is fully activated and regulated when integrated into the r...
Article
Full-text available
Rotating flagella propel bacteria toward favorable environments. Sense of rotation is determined by the intracellular response regulator CheY, which when phosphorylated (CheY-P) interacts directly with the flagellar motor. In many different types of bacteria, the CheC/CheX/FliY (CXY) family of phosphatases terminates the CheY-P signal. Unlike CheC...

Citations

... Besides the most recorded O-phosphorylation on serine, threonine, and tyrosine, the phosphorylation of 1-histidine (1-pHis), 3-histidine (3-pHis) 3,4 , lysine (pLys) 5,6 , and arginine (pArg) 7,8 , termed as N-phosphorylation (N-pho, Fig. 1), has been observed for decades but there is a lack of study. Since firstly reported by Boyer [9][10][11] , pHis has been identified to function in two/multicomponent signaling systems in prokaryotes and lower eukaryotes. A bacterial arginine kinase (McsB) phosphorylates arginine residues of the heatshock regulator (CtsR) in the DNA binding domain, to regulate gene transcription 12,13 . ...
... Tm CheA has two autophosphorylation levels: a receptor-complexed "sequestered" conformation that constrains the P1 domains and an "open" conformation that enables P1-CheY interaction ( Figure 1B) 4,27 . P1 phosphorylation decreases dramatically upon receptor inhibition 28 . Due to the long and flexible L1 and L2 linkers, the release of constrained P1 from the kinase core domains P3-P5 increases the hydrodynamic radius of the CheA dimer considerably, as evidenced by SAXS measurements 29,30 . ...
... FliG connects the central MS-ring formed by FliF to the motor and stator components 34,35 , while FliM and FliY are involved in accepting CheY-P thus leading to conformational changes within the C-ring followed by a directional change in flagellar rotation [36][37][38] . CheY-P is rapidly dephosphorylated through its autophosphatase activity 39 but also through the phosphatase activity of FliM and FliY in some bacterial species 38,40 . This rapid CheY recycling ensures a fast and reliable response towards chemotactic signals. ...