The DNA-polymerase inhibiting activity of poly(beta-l-malic acid) in nuclear extract during the cell cycle of Physarum polycephalum.

The naturally synchronous plasmodia of myxomycetes synthesize poly(beta-l-malic acid), which carries out cell-specific functions. In Physarum polycephalum, poly(beta-l-malate) [the salt form of poly(beta-l-malic acid)] is highly concentrated in the nuclei, repressing DNA synthetic activity of DNA polymerases by the formation of reversible complexes. To test whether this inhibitory activity is cell-cycle-dependent, purified DNA polymerase alpha of P.