Structural Analysis of Phosphonopyruvate Decarboxylase RhiEF: First Insights into an Ancestral Heterooligomeric Thiamine Pyrophosphate-Dependent Decarboxylase.
Nakamura, A., Shiina, A., Fukaya, T., Seki, Y., Momiyama, M., Kojima, S.(2024) Biochemistry 63: 3250-3260
- PubMed: 39586109 
- DOI: https://doi.org/10.1021/acs.biochem.4c00559
- Primary Citation of Related Structures:  
9IZ3, 9IZ4 - PubMed Abstract: 
The RhiE and RhiF proteins work together as RhiEF and function as a thiamine pyrophosphate (TPP)-dependent phosphonopyruvate decarboxylase to produce phosphonoacetaldehyde in the rhizocticin biosynthesis pathway. In this study, we determined the crystal structure of the RhiEF complexed with TPP and Mg 2+ . RhiEF forms a dimer of heterodimers, and the cofactor TPP is bound at the heterotetrameric subunit interface. Structural analysis of RhiEF revealed that the RhiE and RhiF moieties correspond to the pyrimidine-binding (PYR) and pyrophosphate-binding (PP) domains commonly found in TPP-dependent enzymes, respectively, as predicted by amino acid sequence alignment analysis. In contrast to other TPP-dependent enzymes with known structures, RhiEF has no domains other than the PYR and PP domains. Furthermore, structure-based evolutionary and sequence-based phylogenetic analyses have suggested that heteromultimeric enzymes such as RhiEF are ancestral types. These results indicate that RhiEF is one of the smallest and most ancient TPP-dependent decarboxylases. Based on the structural comparisons of RhiEF with other TPP-dependent decarboxylases, we identified the amino acid residues responsible for the catalytic mechanism of TPP-dependent decarboxylation in RhiEF.
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan.
Organizational Affiliation: