X-ray diffraction
2.01Å resolution

Crystal structure of the human sliding clamp at 2.0 angstrom resolution

Source organism: Homo sapiens
Primary publication:
p21 Exploits Residue Tyr151 as a Tether for High-Affinity PCNA Binding.
Biochemistry 54 3483-93 (2015)
PMID: 25972089

Function and Biology Details

Structure analysis Details

Assembly composition:
hetero hexamer (preferred)
Entry contents:
2 distinct polypeptide molecules
Macromolecules (2 distinct):
Proliferating cell nuclear antigen Chains: A, C, E
Molecule details ›
Chains: A, C, E
Length: 261 amino acids
Theoretical weight: 28.8 KDa
Source organism: Homo sapiens
Expression system: Escherichia coli
  • Canonical: P12004 (Residues: 1-261; Coverage: 100%)
Gene name: PCNA
Sequence domains:
Structure domains: Proliferating Cell Nuclear Antigen
Cyclin-dependent kinase inhibitor 1 Chains: B, D, F
Molecule details ›
Chains: B, D, F
Length: 22 amino acids
Theoretical weight: 2.76 KDa
Source organism: Homo sapiens
Expression system: Not provided
  • Canonical: P38936 (Residues: 139-160; Coverage: 13%)
Gene names: CAP20, CDKN1, CDKN1A, CIP1, MDA6, PIC1, SDI1, WAF1

Ligands and Environments

No bound ligands
No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: RIGAKU MICROMAX-007 HF
Spacegroup: P3
Unit cell:
a: 142.97Å b: 142.97Å c: 41.41Å
α: 90° β: 90° γ: 120°
R R work R free
0.155 0.148 0.189
Expression systems:
  • Escherichia coli
  • Not provided