5z38 | pdb_00005z38
Crystal structure of CsrA bound to CesT
Structural highlights
Function[CSRA_ECO27] A key translational regulator that binds mRNA to regulate translation initiation and/or mRNA stability. Mediates global changes in gene expression, shifting from rapid growth to stress survival by linking envelope stress, the stringent response and the catabolite repression systems. Usually binds in the 5'-UTR; binding at or near the Shine-Dalgarno sequence prevents ribosome-binding, repressing translation, binding elsewhere in the 5'-UTR can activate translation and/or stabilize the mRNA. Its function is antagonized by small RNA(s). Publication Abstract from PubMedThe 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. Molecular 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 GF, Lu G Nat Commun. 2018 Mar 22;9(1):1196. doi: 10.1038/s41467-018-03625-x. PMID:29567971[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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