Protein-PCNA interactions: a DNA-scanning mechanism?

Abstract

Proliferating-cell nuclear antigen (PCNA) plays an essential role in nucleic-acid metabolism in all eukaryotes. The PCNA protein interacts with a large number of proteins. These proteins can be divided into two groups: the first contains proteins that have a known enzymatic activity; the second contains regulatory proteins that are involved in cell-cycle progression, checkpoint control and cellular differentiation. Interestingly, all of the enzymes known to interact with PCNA either recognize specific structures on DNA or have limited DNA-sequence specificity. Proteins that have low sequence specificities could utilize PCNA as an adapter in order to interact with their DNA substrates.