Download MendeleyBranched signal wiring of an essential bacterial cell-cycle phosphotransfer protein.
Blair, J.A., Xu, Q., Childers, W.S., Mathews, I.I., Kern, J.W., Eckart, M., Deacon, A.M., Shapiro, L.(2013) Structure 21: 1590-1601
- PubMed: 23932593
- DOI: https://doi.org/10.1016/j.str.2013.06.024
- Primary Citation of Related Structures:
4FMT - PubMed Abstract:
Vital to bacterial survival is the faithful propagation of cellular signals, and in Caulobacter crescentus, ChpT is an essential mediator within the cell-cycle circuit. ChpT functions as a histidine-containing phosphotransfer protein (HPt) that shuttles a phosphoryl group from the receiver domain of CckA, the upstream hybrid histidine kinase (HK), to one of two downstream response regulators (CtrA or CpdR) that controls cell-cycle progression. To understand how ChpT interacts with multiple signaling partners, we solved the crystal structure of ChpT at 2.3 Å resolution. ChpT adopts a pseudo-HK architecture but does not bind ATP. We identified two point mutation classes affecting phosphotransfer and cell morphology: one that globally impairs ChpT phosphotransfer, and a second that mediates partner selection. Importantly, a small set of conserved ChpT residues promotes signaling crosstalk and contributes to the branched signaling that activates the master regulator CtrA while inactivating the CtrA degradation signal, CpdR.
Organizational Affiliation:
Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
