| Structural highlights
Function
CSRA_ECOLI Binds to mRNA to regulate post-transcriptional activity. Affects glycogen biosynthesis, gluconeogenesis, cell size and surface properties. Regulates glycogen synthesis under both aerobic and anaerobic conditions. Seems to accelerate the degradation of glg gene transcripts, potentially through selective RNA binding. Acts to inhibit interaction between the LetD protein and the A subunit of DNA gyrase. Also required for motility and flagellum biosynthesis through the post-transcriptional activation of flhDC expression. This involves binding to and stabilization of the flhDC message by CsrA. Binds to and reduces levels of probable diguanylate cyclases ycdT and ydeH.[1] [2] [3]
Publication Abstract from PubMed
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.
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[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wei BL, Brun-Zinkernagel AM, Simecka JW, Pruss BM, Babitzke P, Romeo T. Positive regulation of motility and flhDC expression by the RNA-binding protein CsrA of Escherichia coli. Mol Microbiol. 2001 Apr;40(1):245-56. PMID:11298291
- ↑ Jonas K, Edwards AN, Simm R, Romeo T, Romling U, Melefors O. The RNA binding protein CsrA controls cyclic di-GMP metabolism by directly regulating the expression of GGDEF proteins. Mol Microbiol. 2008 Oct;70(1):236-57. doi: 10.1111/j.1365-2958.2008.06411.x. Epub, 2008 Aug 18. PMID:18713317 doi:http://dx.doi.org/10.1111/j.1365-2958.2008.06411.x
- ↑ Boehm A, Steiner S, Zaehringer F, Casanova A, Hamburger F, Ritz D, Keck W, Ackermann M, Schirmer T, Jenal U. Second messenger signalling governs Escherichia coli biofilm induction upon ribosomal stress. Mol Microbiol. 2009 Jun;72(6):1500-16. doi: 10.1111/j.1365-2958.2009.06739.x., Epub 2009 May 15. PMID:19460094 doi:10.1111/j.1365-2958.2009.06739.x
- ↑ Ye F, Yang F, Yu R, Lin X, Qi J, Chen Z, Cao Y, Wei Y, Gao GF, Lu G. Molecular basis of binding between the global post-transcriptional regulator CsrA and the T3SS chaperone CesT. Nat Commun. 2018 Mar 22;9(1):1196. doi: 10.1038/s41467-018-03625-x. PMID:29567971 doi:http://dx.doi.org/10.1038/s41467-018-03625-x
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