A heterotrimeric PCNA in the hyperthermophilic archaeon Sulfolobus solfataricus.
The sliding clamp, PCNA, of the archaeon Sulfolobus solfataricus P2 is a heterotrimer of three distinct subunits (PCNA1, 2, and 3) that assembles in a defined manner. The PCNA heterotrimer, but not individual subunits, stimulates the activities of the DNA polymerase, DNA ligase I, and the flap endonuclease (FEN1) of S. solfataricus. Distinct PCNA subunits contact DNA polymerase, DNA ligase, or FEN1, imposing a defined architecture at the lagging strand fork and suggesting the existence of a preformed scanning complex at the fork. This provides a mechanism to tightly couple DNA synthesis and Okazaki fragment maturation. Additionally, unique subunit-specific interactions between components of the clamp loader, RFC, suggest a model for clamp loading of PCNA.
Dionne
Isabelle
I
Medical Research Council Cancer Cell Unit, Hutchison MRC Research Centre, Hills Road, Cambridge CB2 2XZ, United Kingdom.
Nookala
Ravi K
RK
Jackson
Stephen P
SP
Doherty
Aidan J
AJ
Bell
Stephen D
SD
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019641:DNA, Archaeal / Q000235:genetics / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D021122:Protein Subunits / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D016944:Sulfolobus / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D019843:Archaeal Proteins; D019641:DNA, Archaeal; D018809:Proliferating Cell Nuclear Antigen; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D004259:DNA-Directed DNA Polymerase