Crystallization and preliminary crystallographic analysis of the complex of the second and third regulatory subunits of human Pol delta.

Human DNA polymerase delta (Pol delta) consists of four subunits: p125, p50, p66 and p12. A heterodimer containing a His-tagged p50 subunit (p50) and a p50-interacting domain of the p66 subunit (p66(N)) was crystallized. The crystal was in the form of a prism with a rhombic cross-section and belonged to space group P2(1). The crystal had unit-cell parameters a = 95.13, b = 248.54, c = 103.46 A, beta = 106.94 degrees and diffracted to a resolution of 3 A. Four molecules of p50-p66(N) in an asymmetric unit corresponded to a crystal solvent content of 72.2%.