Download MendeleyMolecular basis of binding between the global post-transcriptional regulator CsrA and the T3SS chaperone CesT
Ye, F., Yang, F., Yu, R., Lin, X., Qi, J., Chen, Z., Cao, Y., Wei, Y., Gao, G.F., Lu, G.(2018) Nat Commun 9: 1196-1196
- PubMed: 29567971
- DOI: https://doi.org/10.1038/s41467-018-03625-x
- Primary Citation of Related Structures:
5Z38 - PubMed Abstract:
The T3SS chaperone CesT is recently shown to interact with the post-transcriptional regulator CsrA to modulate post-attachment signaling in enteropathogenic and enterohemorrhagic Escherichia coli. The molecular basis of the CesT/CsrA binding, however, remains elusive. Here, we show that CesT and CsrA both created two ligand binding sites in their homodimers, forming irregular multimeric complexes in solution. Through construction of a recombinant CsrA-dimer (Re-CsrA) that contains a single CesT binding site, the atomic binding features between CesT and CsrA are delineated via the structure of the CesT/Re-CsrA complex. In contrast to a previously reported N-terminally swapped dimer-form, CesT adopts a dimeric architecture with a swapped C-terminal helix for CsrA engagement. In CsrA, CesT binds to a surface patch that extensively overlaps with its mRNA binding site. The binding mode therefore justifies a mechanism of CsrA-modulation by CesT via competitive inhibition of the CsrA/mRNA interactions.
Organizational Affiliation:
West China Hospital Emergency Department (WCHED), State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu, Sichuan, 610041, China.
