A novel PCNA-binding motif identified by the panning of a random peptide display library.
Proliferating cell nuclear antigen (PCNA) has recently been identified as a target for the binding of proteins involved in DNA replication, DNA repair, and cell cycle control. The interactions between PCNA and a number of these proteins are known to be mediated by a conserved peptide motif. In this study, a random peptide library in which peptide sequences are displayed on the E. coli bacterial flagellin protein was screened for PCNA-binding sequences. Analysis of the retrieved peptide sequences verified the presence of the known PCNA-binding motif. In addition, a second, larger group of peptides containing a different consensus sequence for PCNA binding was discovered. This sequence was found to be present on DNA polymerase delta, and a peptide conforming to this sequence was demonstrated to bind to PCNA. Database search and analysis show that many proteins contain the second consensus sequence. These include proteins that are involved in DNA replication, repair, and cell cycle control. The demonstration of this second PCNA-binding motif may provide a basis for identifying and experimentally testing specific proteins for the structural basis for PCNA binding.
Xu
H
H
Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, USA.
Zhang
P
P
Liu
L
L
Lee
M Y
MY
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D020650:Combinatorial Chemistry Techniques; D006224:Cricetinae; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics; D005408:Flagellin / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D019151:Peptide Library; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000138:chemical synthesis / Q000378:metabolism; D013879:Thioredoxins / Q000235:genetics
D019151:Peptide Library; D010455:Peptides; D018809:Proliferating Cell Nuclear Antigen; D011993:Recombinant Fusion Proteins; D005408:Flagellin; D013879:Thioredoxins