Mitochondrial electrogenic aspartate/glutamate antiporter that favors efflux of aspartate and entry of glutamate and proton within the mitochondria as part of the malate-aspartate shuttle (By similarity). Also mediates the uptake of L-cysteinesulfinate by mitochondria in exchange of L-glutamate and proton. Can also exchange L-cysteinesulfinate with aspartate in their anionic form without any proton translocation (By similarity). H(+)(out) + L-aspartate(in) + L-glutamate(out) = H(+)(in) + L-aspartate(out) + L-glutamate(in) 3-sulfino-L-alanine(out) + H(+)(in) + L-glutamate(in) = 3-sulfino-L-alanine(in) + H(+)(out) + L-glutamate(out) 3-sulfino-L-alanine(out) + L-aspartate(in) = 3-sulfino-L-alanine(in) + L-aspartate(out) Homodimer (via N-terminus). The EF-hand 2 domain within the regulatory N-terminal domain binds one calcium in the mitochondrial intermembrane space. Calcium triggers the binding of the regulatory N-terminal domain to the C-terminal domain, opening a vestibule which allows the substrates to be translocated through the carrier domain. In the absence of calcium, the linker loop domain may close the vestibule and prevent substrates from entering the carrier domain. Belongs to the mitochondrial carrier (TC 2.A.29) family.