1PAF

THE 2.5 ANGSTROMS STRUCTURE OF POKEWEED ANTIVIRAL PROTEIN

Summary for 1PAF

• Entry DOI: 10.2210/pdb1paf/pdb
• Descriptor: POKEWEED ANTIVIRAL PROTEIN (2 entities in total)
• Functional Keywords: protein synthesis inhibitor
• Biological source: Phytolacca americana (American pokeweed)
• Total number of polymer chains: 2
• Total formula weight: 58682.93

Authors

Monzingo, A.F.,Collins, E.J.,Ernst, S.R.,Irvin, J.D.,Robertus, J.D. (deposition date: 1992-10-19, release date: 1994-01-31, Last modification date: 2024-10-09)

Primary citation

Monzingo, A.F.,Collins, E.J.,Ernst, S.R.,Irvin, J.D.,Robertus, J.D.
The 2.5 A structure of pokeweed antiviral protein.
J.Mol.Biol., 233:705-715, 1993

PubMed Abstract: The pokeweed antiviral protein (PAP), isolated from the leaves of Phytolacca americana, is one of a family of plant and bacterial ribosome-inhibiting proteins (RIPs) which act as specific N-glycosidases on rRNA. Here we report the three-dimensional structure of PAP determined to 2.5 A resolution by X-ray crystallography. After 14 rounds of refinement, the R factor is 0.17 for 5.0 to 2.5 A data. The protein is homologous with the A chain of ricin and exhibits a very similar folding pattern. The positions of key active site residues are also similar. We also report the 2.8 A structure of PAP complexed with a substrate analog, formycin 5'-monophosphate. As seen previously in ricin, the formycin ring is stacked between invariant tyrosines 72 and 123. Arg179 bonds to N-3 which is thought to be important in catalysis.

PubMed: 8411176
DOI: 10.1006/jmbi.1993.1547

Experimental method

X-RAY DIFFRACTION (2.5 Å)