PMID: 23621882

Authors:

Thoden JB, Branch MC, Zimmer AL, Bruender NA, Holden HM

Title:

Active Site Architecture of a Sugar N-Oxygenase.

Journal:

Biochemistry. 2013 Apr 30.

Abstract:

KijD3 is a flavin-dependent N-oxygenase implicated in the formation of the nitro-containing sugar d-kijanose, found attached to the antibiotic kijanimicin. For this investigation, the structure of KijD3 in complex with FMN and its dTDP-sugar substrate was solved to 2.1 A resolution. In contrast to the apoenzyme structure, the C-terminus of the protein becomes ordered and projects into the active site cleft [Bruender, N. A., Thoden, J. B., and Holden, H. M. (2010) Biochemistry 49, 3517-3524]. The amino group of the dTDP-aminosugar that is oxidized is located 4.9 A from C4a of the flavin ring. The model provides a molecular basis for understanding the manner in which KijD3 catalyzes its unusual chemical transformation.