Heterodimer of CABP1A and CABP1B. CABP1A/CABP1B could also associate with p31/p34 to form an active complex. Belongs to the CAPAB/TerDEXZ family. The gene for this protein is duplicated in strains AX3 and AX4. These strains contain a duplication of a segment of 750 kb of chromosome 2 compared to the corresponding sequence in strain AX2.