1EF0

CRYSTAL STRUCTURE OF PI-SCEI MINIPRECURSOR

Summary for 1EF0

• Entry DOI: 10.2210/pdb1ef0/pdb
• Descriptor: PI-SCEI ENDONUCLEASE, ZINC ION (3 entities in total)
• Functional Keywords: endonuclease, protein splicing, mini-precursor, hydrolase
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Total number of polymer chains: 2
• Total formula weight: 103738.44

Authors

Poland, B.W.,Xu, M.-Q.,Quiocho, F.A. (deposition date: 2000-02-04, release date: 2000-06-07, Last modification date: 2024-02-07)

Primary citation

Poland, B.W.,Xu, M.Q.,Quiocho, F.A.
Structural insights into the protein splicing mechanism of PI-SceI.
J.Biol.Chem., 275:16408-16413, 2000

PubMed Abstract: PI-SceI is a member of a class of proteins (inteins) that excise themselves from a precursor protein and in the process ligate the flanking protein sequences (exteins). We report here the 2.1-A resolution crystal structure of a PI-SceI miniprecursor (VMA29) containing 10 N-terminal extein residues and 4 C-terminal extein residues. Mutations at the N- and C-terminal splicing junctions, blocking in vivo protein splicing, allowed the miniprecursor to be purified and crystallized. The structure reveals both the N- and C-terminal scissile peptide bonds to be in distorted trans conformations (tau approximately 100 degrees ). Modeling of the wild-type PI-SceI based on the VMA29 structure indicates a large conformational change (movement of >9 A) must occur to allow transesterification to be completed. A zinc atom was discovered at the C-terminal splicing junction. Residues Cys(455), His(453), and Glu(80) along with a water molecule (Wat(53)) chelate the zinc atom. The crystal structure of VMA29 has captured the intein in its pre-spliced state.

PubMed: 10828056
DOI: 10.1074/jbc.275.22.16408

Experimental method

X-RAY DIFFRACTION (2.1 Å)