Component of a regulatory phosphorelay system that controls B.abortus cell growth, division, and intracellular survival inside mammalian host cells. This signaling pathway is composed of CckA, ChpT, CtrA and CpdR. ChpT efficiently and specifically shuttles phosphoryl groups from the CckA kinase to the receiver domains of both CtrA and CpdR. Does not bind ATP. Overexpression of chpT results in a defect in cell morphology, DNA content, and intracellular survival in human macrophages. Homodimer. Forms an asymmetric heterotetramer with CtrA (2:2). There are at least two modes of interaction between ChpT and CtrA, only one of which is competent to catalyze His-Asp phosphoryl transfer. Each ChpT monomer is composed of an N-terminal dimerization and histidine phosphotransfer (DHp) domain and a C-terminal domain that is structurally similar to the catalytic and ATP-binding domain found in histidine kinases but that lacks regions required for ATP binding. Is phosphorylated by CckA-P on His-22. This gene cannot be deleted or disrupted in the absence of a complementary copy expressed in trans, indicating this gene is essential in B.abortus. Belongs to the ChpT phosphotransferase family.