From Proteopedia

University of Massachusetts Amherst Chemistry-Biology Interface Program at UMass Amherst and on display at the Molecular Playground.

Chemotaxis receptors

The bacterial chemotaxis receptors are transmembrane receptors with a simple signalling pathway which has elements relevant to the general understanding of signal recognition and transduction across membranes, how signals are relayed between molecules in a pathway, and how adaptation to a persistent signal is achieved.

Bacterial chemotaxis receptors are composed of a ligand-binding domain, a transmembrane domain consisting of two helices TM1 and TM2, and a cytoplasmic domain. All known bacterial chemotaxis receptors have a highly conserved cytoplasmic domain, which unites signals from different ligand domains into a single signalling pathway to flagella motors.

3D structures of methyl-accepting chemotaxis protein

The structure of the cytoplasmic domain of a serine chemotaxis receptor(TSR) of Escherichia coli is a 200 A-long coiled-coil of two antiparallel helices connected by a 'U-turn'. Two of these domains form a long, supercoiled, four-helical bundle in the cytoplasmic portion of the receptor.

For a list of PDBs see Chemotaxis protein

Chemoreceptor array

Transmembrane receptors, histidine kinases (CheA) and coupling protein (CheW) form an organized array at cell membrane. In the array, six trimers of receptor dimers combined vertically in a hexagonal lattice with CheA regulatory domains (P5) and CheW surrounded. Whereas the CheA kinase domains (P4) lie downward below the ring, the CheA dimerization domains (P3) link neighboring rings to extend the array.

Related molecule

Molecular Playground/CheA,Molecular Playground/Bacterial Chemotaxis Receptors,Molecular Playground/Cytoplasmic domain of chemoreceptor of Thermotoga maritima,Methyl-accepting chemotaxis protein

Reference

1.Four-helical-bundle structure of the cytoplasmic domain of a serine chemotaxis receptor., Kim KK, Yokota H, Kim SH, Nature. 1999 Aug 19;400(6746):787-92. 2.Molecular architecture of chemoreceptor arrays revealed by cryoelectron tomography of Escherichia coli minicells, Ariane Briege, Xiaoxiao Li and et.al., PNAS.2012 Mar 6;109(10):3766-3771