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.
2og5
From Proteopedia
Crystal structure of asparagine oxygenase (AsnO)
Overview
Non-ribosomally synthesized lipopeptide antibiotics of the daptomycin type are known to contain unnatural beta-modified amino acids, which are essential for bioactivity. Here we present the biochemical and structural basis for the incorporation of 3-hydroxyasparagine at position 9 in the 11-residue acidic lipopeptide lactone calcium-dependent antibiotic (CDA). Direct hydroxylation of l-asparagine by AsnO, a non-heme Fe(2+)/alpha-ketoglutarate-dependent oxygenase encoded by the CDA biosynthesis gene cluster, was validated by Fmoc derivatization of the reaction product and LC/MS analysis. The 1.45, 1.92, and 1.66 A crystal structures of AsnO as apoprotein, Fe(2+) complex, and product complex, respectively, with (2S,3S)-3-hydroxyasparagine and succinate revealed the stereoselectivity and substrate specificity of AsnO. The comparison of native and product-complex structures of AsnO showed a lid-like region (residues F208-E223) that seals the active site upon substrate binding and shields it from sterically demanding peptide substrates. Accordingly, beta-hydroxylated asparagine is synthesized prior to its incorporation into the growing CDA peptide. The AsnO structure could serve as a template for engineering novel enzymes for the synthesis of beta-hydroxylated amino acids.
About this Structure
2OG5 is a Single protein structure of sequence from Streptomyces coelicolor. Full crystallographic information is available from OCA.
Reference
Mechanistic and structural basis of stereospecific Cbeta-hydroxylation in calcium-dependent antibiotic, a daptomycin-type lipopeptide., Strieker M, Kopp F, Mahlert C, Essen LO, Marahiel MA, ACS Chem Biol. 2007 Mar 20;2(3):187-96. PMID:17373765 Page seeded by OCA on Sun May 4 10:50:26 2008
