title: Clostridium difficile Hfq can replace Escherichia coli Hfq for most of its function.
abstract: A gene for the Hfq protein is present in the majority of sequenced bacterial genomes. Its characteristic hexameric ring-like core structure is formed by the highly conserved N-terminal regions. In contrast, the C-terminal forms an extension, which varies in length, lacks homology, and is predicted to be unstructured. In Gram-negative bacteria, Hfq facilitates the pairing of sRNAs with their mRNA target and thus affects gene expression, either positively or negatively, and modulates sRNA degradation. In Gram-positive bacteria, its role is still poorly characterized. Numerous sRNAs have been detected in many Gram-positive bacteria, but it is not yet known whether these sRNAs act in association with Hfq. Compared with all other Hfqs, the C. difficile Hfq exhibits an unusual C-terminal sequence with 75% asparagine and glutamine residues, while the N-terminal core part is more conserved. To gain insight into the functionality of the C. difficile Hfq (Cd-Hfq) protein in processes regulated by sRNAs, we have tested the ability of Cd-Hfq to fulfill the functions of the E. coli Hfq (Ec-Hfq) by examining various functions associated with Hfq in both positive and negative controls of gene expression. We found that Cd-Hfq substitutes for most but not all of the tested functions of the Ec-Hfq protein. We also investigated the role of the C-terminal part of the Hfq proteins. We found that the C-terminal part of both Ec-Hfq and Cd-Hfq is not essential but contributes to some functions of both the E. coli and C. difficile chaperons.
authors.affiliation: CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France.
authors.forename: Joel
authors.initials: J
authors.lastname: Caillet
authors.affiliation: CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Gracia
authors.affiliation: CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France.
authors.forename: Fanette
authors.initials: F
authors.lastname: Fontaine
authors.affiliation: CNRS FRE3630 (previously UPR9073), University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France eliane.hajnsdorf@ibpc.fr.
authors.forename: Eliane
authors.initials: E
authors.lastname: Hajnsdorf
mesh_terms: D016360:Clostridioides difficile / Q000235:genetics* / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D035001:Host Factor 1 Protein / Q000235:genetics* / Q000378:metabolism*; D010641:Phenotype; D011485:Protein Binding; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D035001:Host Factor 1 Protein; D012329:RNA, Bacterial; D012333:RNA, Messenger; D001616:beta-Galactosidase
keywords: Clostridium difficile; Escherichia coli; Hfq; gene expression; small noncoding RNAs