Structural insights into RapZ-mediated regulation of bacterial amino-sugar metabolism.
Gonzalez, G.M., Durica-Mitic, S., Hardwick, S.W., Moncrieffe, M.C., Resch, M., Neumann, P., Ficner, R., Gorke, B., Luisi, B.F.(2017) Nucleic Acids Res 45: 10845-10860
- PubMed: 28977623 
- DOI: https://doi.org/10.1093/nar/gkx732
- Primary Citation of Related Structures:  
5O5O, 5O5Q, 5O5S - PubMed Abstract: 
In phylogenetically diverse bacteria, the conserved protein RapZ plays a central role in RNA-mediated regulation of amino-sugar metabolism. RapZ contributes to the control of glucosamine phosphate biogenesis by selectively presenting the regulatory small RNA GlmZ to the essential ribonuclease RNase E for inactivation. Here, we report the crystal structures of full length Escherichia coli RapZ at 3.40 Å and 3.25 Å, and its isolated C-terminal domain at 1.17 Å resolution. The structural data confirm that the N-terminal domain of RapZ possesses a kinase fold, whereas the C-terminal domain bears closest homology to a subdomain of 6-phosphofructokinase, an important enzyme in the glycolytic pathway. RapZ self-associates into a domain swapped dimer of dimers, and in vivo data support the importance of quaternary structure in RNA-mediated regulation of target gene expression. Based on biochemical, structural and genetic data, we suggest a mechanism for binding and presentation by RapZ of GlmZ and the closely related decoy sRNA, GlmY. We discuss a scenario for the molecular evolution of RapZ through re-purpose of enzyme components from central metabolism.
Organizational Affiliation: 
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.