This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2rdq
From Proteopedia
|
Crystal Structure of PtlH with Fe/alpha ketoglutarate bound
Overview
The non-heme iron dioxygenase PtlH from the soil organism Streptomyces, avermitilis is a member of the iron(II)/alpha-ketoglutarate-dependent, dioxygenase superfamily and catalyzes an essential reaction in the, biosynthesis of the sesquiterpenoid antibiotic pentalenolactone. To, investigate the structural basis for substrate recognition and catalysis, we have determined the x-ray crystal structure of PtlH in several, complexes with the cofactors iron, alpha-ketoglutarate, and the, non-reactive enantiomer of the substrate, ent-1-deoxypentalenic acid, in, four different crystal forms to up to 1.31A resolution. The overall, structure of PtlH forms a double-stranded barrel helix fold, and the, cofactor-binding site for iron and alpha-ketoglutarate is similar to other, double-stranded barrel helix fold enzymes. Additional secondary structure, elements that contribute to the substrate-binding site in PtlH are not, conserved in other double-stranded barrel helix fold enzymes. Binding of, the substrate enantiomer induces a reorganization of the monoclinic, crystal lattice leading to a disorder-order transition of a C-terminal, alpha-helix. The newly formed helix blocks the major access to the active, site and effectively traps the bound substrate. Kinetic analysis of wild, type and site-directed mutant proteins confirms a critical function of two, arginine residues in substrate binding, while simulated docking of the, enzymatic reaction product reveals the likely orientation of bound, substrate.
About this Structure
2RDQ is a Single protein structure of sequence from Streptomyces avermitilis with , and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal Structure of the Non-heme Iron Dioxygenase PtlH in Pentalenolactone Biosynthesis., You Z, Omura S, Ikeda H, Cane DE, Jogl G, J Biol Chem. 2007 Dec 14;282(50):36552-60. Epub 2007 Oct 16. PMID:17942405
Page seeded by OCA on Wed Jan 23 11:24:00 2008
Categories: Single protein | Streptomyces avermitilis | Cane, D.E. | Ikeda, H. | Jogl, G. | Omura, S. | You, Z. | AKG | FE | MG | Dioxygenase | Double stranded barrel helix | Oxidoreductase
