The 143Tb nucleus has been studied with the 92Mo (54Fe, 3pγ) reaction at 240-MeV incident energy, extending the systematics of odd-A, N=78 isotones to higher Z. For the yrast band, excited states up to a spin of 59/2- have been observed. The first allowed backbend occurs at a rotational frequency of ħω=0.38MeV. Three- and five-quasiparticle structures were identified, similar to those seen in lower mass N=78 isotones. Two of these structures have characteristics typical of mixed proton-neutron oblate configurations with one pair of aligned h11/2 neutrons. In addition, two bands consisting of stretched E2 transitions have been observed with no known analogous structures in neighboring nuclei. The results are discussed in terms of the cranking model.