Joern Krausze1, Thomas W Hercher1, Dagmar Zwerschke1, Martin L Kirk2, Wulf Blankenfeldt3,4, Ralf R Mendel1, Tobias Kruse5. 1. Department of Plant Biology, Braunschweig University of Technology, 38106 Braunschweig, Germany. 2. Department of Chemistry and Chemical Biology, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001, U.S.A. 3. Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany. 4. Department for Biotechnology, Institute of Biochemistry, Biotechnology and Bioinformatics, Braunschweig University of Technology, Spielmannstrasse 7, 38106 Braunschweig, Germany. 5. Department of Plant Biology, Braunschweig University of Technology, 38106 Braunschweig, Germany t.kruse@tu-bs.de.
Abstract
The molybdenum cofactor (Moco) is a redox-active prosthetic group found in the active site of Moco-dependent enzymes, which are vitally important for life. Moco biosynthesis involves several enzymes that catalyze the subsequent conversion of GTP into cyclic pyranopterin monophosphate (cPMP), molybdopterin (MPT), adenylated MPT (MPT-AMP), and finally Moco. While the underlying principles of cPMP, MPT, and MPT-AMP formation are well understood, the molybdenum insertase (Mo-insertase)-catalyzed final Moco maturation step is not. In the present study, we analyzed high-resolution X-ray datasets of the plant Mo-insertase Cnx1E that revealed two molybdate-binding sites within the active site, hence improving the current view on Cnx1E functionality. The presence of molybdate anions in either of these sites is tied to a distinctive backbone conformation, which we suggest to be essential for Mo-insertase molybdate selectivity and insertion efficiency.
The an class="Chemical">molybdenum cofactor (Moco) is a redox-active prosthetic group found in the active site of Moco-dependent enzymes, which are vitally important for life. Moco biosynthesis involves several enzymes that catalyze the subsequent conversion of n class="Chemical">GTP into cyclic pyranopterin monophosphate (cPMP), molybdopterin (MPT), adenylated MPT (MPT-AMP), and finally Moco. While the underlying principles of cPMP, MPT, and MPT-AMP formation are well understood, the molybdenum insertase (Mo-insertase)-catalyzed final Moco maturation step is not. In the present study, we analyzed high-resolution X-ray datasets of the plant Mo-insertase Cnx1E that revealed two molybdate-binding sites within the active site, hence improving the current view on Cnx1E functionality. The presence of molybdate anions in either of these sites is tied to a distinctive backbone conformation, which we suggest to be essential for Mo-insertase molybdate selectivity and insertion efficiency.
Authors: Corinna Probst; Jing Yang; Joern Krausze; Thomas W Hercher; Casseday P Richers; Thomas Spatzal; Khadanand Kc; Logan J Giles; Douglas C Rees; Ralf R Mendel; Martin L Kirk; Tobias Kruse Journal: Nat Chem Date: 2021-06-28 Impact factor: 24.427