The p12 subunit of human polymerase delta uses an atypical PIP-box for molecular recognition of proliferating cell nuclear antigen (PCNA)

The atomic coordinates and structure factors (code 6HVO) have been deposited in the Protein Data Bank (http://wwpdb.org/). The NMR resonance data of this paper have been deposited in the Biological Magnetic Resonance Data Bank under BMRB accession codes 27661 and 27662, respectively.