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Dobrzanski T, Pobre V, Moreno LF, Barbosa HCDS, Monteiro RA, de Oliveira Pedrosa F, de Souza EM, Arraiano CM, Steffens MBR. In silico prediction and expression profile analysis of small non-coding RNAs in Herbaspirillum seropedicae SmR1. BMC Genomics 2020; 21:134. [PMID: 32039705 PMCID: PMC7011215 DOI: 10.1186/s12864-019-6402-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 12/15/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Herbaspirillum seropedicae is a diazotrophic bacterium from the β-proteobacteria class that colonizes endophytically important gramineous species, promotes their growth through phytohormone-dependent stimulation and can express nif genes and fix nitrogen inside plant tissues. Due to these properties this bacterium has great potential as a commercial inoculant for agriculture. The H. seropedicae SmR1 genome is completely sequenced and annotated but despite the availability of diverse structural and functional analysis of this genome, studies involving small non-coding RNAs (sRNAs) has not yet been done. We have conducted computational prediction and RNA-seq analysis to select and confirm the expression of sRNA genes in the H. seropedicae SmR1 genome, in the presence of two nitrogen independent sources and in presence of naringenin, a flavonoid secreted by some plants. RESULTS This approach resulted in a set of 117 sRNAs distributed in riboswitch, cis-encoded and trans-encoded categories and among them 20 have Rfam homologs. The housekeeping sRNAs tmRNA, ssrS and 4.5S were found and we observed that a large number of sRNAs are more expressed in the nitrate condition rather than the control condition and in the presence of naringenin. Some sRNAs expression were confirmed in vitro and this work contributes to better understand the post transcriptional regulation in this bacterium. CONCLUSIONS H. seropedicae SmR1 express sRNAs in the presence of two nitrogen sources and/or in the presence of naringenin. The functions of most of these sRNAs remains unknown but their existence in this bacterium confirms the evidence that sRNAs are involved in many different cellular activities to adapt to nutritional and environmental changes.
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Affiliation(s)
- Tatiane Dobrzanski
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná (UFPR), Av. Coronel. Francisco H. dos Santos, 210, PoBox 19046, Curitiba, 81.531-980, Paraná, Brazil
| | - Vânia Pobre
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal.
| | - Leandro Ferreira Moreno
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná (UFPR), Av. Coronel. Francisco H. dos Santos, 210, PoBox 19046, Curitiba, 81.531-980, Paraná, Brazil
| | - Helba Cirino de Souza Barbosa
- Graduate Program in Bioinformatics, Universidade Federal do Paraná (UFPR), Rua Alcides Vieira Arcoverde, 1225, Curitiba, 81520-260, Brazil
| | - Rose Adele Monteiro
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná (UFPR), Av. Coronel. Francisco H. dos Santos, 210, PoBox 19046, Curitiba, 81.531-980, Paraná, Brazil.,Graduate Program in Bioinformatics, Universidade Federal do Paraná (UFPR), Rua Alcides Vieira Arcoverde, 1225, Curitiba, 81520-260, Brazil
| | - Fábio de Oliveira Pedrosa
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná (UFPR), Av. Coronel. Francisco H. dos Santos, 210, PoBox 19046, Curitiba, 81.531-980, Paraná, Brazil
| | - Emanuel Maltempi de Souza
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná (UFPR), Av. Coronel. Francisco H. dos Santos, 210, PoBox 19046, Curitiba, 81.531-980, Paraná, Brazil
| | - Cecília Maria Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Maria Berenice Reynaud Steffens
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná (UFPR), Av. Coronel. Francisco H. dos Santos, 210, PoBox 19046, Curitiba, 81.531-980, Paraná, Brazil.
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Stanek KA, Mura C. Producing Hfq/Sm Proteins and sRNAs for Structural and Biophysical Studies of Ribonucleoprotein Assembly. Methods Mol Biol 2019; 1737:273-299. [PMID: 29484599 DOI: 10.1007/978-1-4939-7634-8_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hfq is a bacterial RNA-binding protein that plays key roles in the post-transcriptional regulation of gene expression. Like other Sm proteins, Hfq assembles into toroidal discs that bind RNAs with varying affinities and degrees of sequence specificity. By simultaneously binding to a regulatory small RNA (sRNA) and an mRNA target, Hfq hexamers facilitate productive RNA∙∙∙RNA interactions; the generic nature of this chaperone-like functionality makes Hfq a hub in many sRNA-based regulatory networks. That Hfq is crucial in diverse cellular pathways-including stress response, quorum sensing, and biofilm formation-has motivated genetic and "RNAomic" studies of its function and physiology (in vivo), as well as biochemical and structural analyses of Hfq∙∙∙RNA interactions (in vitro). Indeed, crystallographic and biophysical studies first established Hfq as a member of the phylogenetically conserved Sm superfamily. Crystallography and other biophysical methodologies enable the RNA-binding properties of Hfq to be elucidated in atomic detail, but such approaches have stringent sample requirements, viz.: reconstituting and characterizing an Hfq·RNA complex requires ample quantities of well-behaved (sufficient purity, homogeneity) specimens of Hfq and RNA (sRNA, mRNA fragments, short oligoribonucleotides, or even single nucleotides). The production of such materials is covered in this chapter, with a particular focus on recombinant Hfq proteins for crystallization experiments.
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Affiliation(s)
- Kimberly A Stanek
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA.
| | - Cameron Mura
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA.
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Santiago-Frangos A, Woodson SA. Hfq chaperone brings speed dating to bacterial sRNA. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1475. [PMID: 29633565 PMCID: PMC6002925 DOI: 10.1002/wrna.1475] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/22/2018] [Accepted: 02/26/2018] [Indexed: 11/11/2022]
Abstract
Hfq is a ubiquitous, Sm-like RNA binding protein found in most bacteria and some archaea. Hfq binds small regulatory RNAs (sRNAs), facilitates base pairing between sRNAs and their mRNA targets, and directly binds and regulates translation of certain mRNAs. Because sRNAs regulate many stress response pathways in bacteria, Hfq is essential for adaptation to different environments and growth conditions. The chaperone activities of Hfq arise from multipronged RNA binding by three different surfaces of the Hfq hexamer. The manner in which the structured Sm core of Hfq binds RNA has been well studied, but recent work shows that the intrinsically disordered C-terminal domain of Hfq modulates sRNA binding, creating a kinetic hierarchy of RNA competition for Hfq and ensuring the release of double-stranded sRNA-mRNA complexes. A combination of structural, biophysical, and genetic experiments reveals how Hfq recognizes its RNA substrates and plays matchmaker for sRNAs and mRNAs in the cell. The interplay between structured and disordered domains of Hfq optimizes sRNA-mediated post-transcriptional regulation, and is a common theme in RNA chaperones. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry.
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Affiliation(s)
- Andrew Santiago-Frangos
- Program in Cellular, Molecular and Developmental Biology and Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Sarah A Woodson
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
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Yucatán in black and red: Linking edaphic analysis and pyrosequencing-based assessment of bacterial and fungal community structures in the two main kinds of soil of Yucatán State. Microbiol Res 2016; 188-189:23-33. [PMID: 27296959 DOI: 10.1016/j.micres.2016.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/16/2016] [Accepted: 04/21/2016] [Indexed: 12/11/2022]
Abstract
Yucatán State is dominated by two kinds of soil, named "Black Leptosol" and "Red Leptosol", which are interwoven across the State. In this work, we analyzed the relation between the edaphic characteristics and the bacterial and fungal community structures in these two kinds of Leptosol. The results revealed that Black Leptosol (BlaS) had a higher content of calcium carbonates, organic matter, nitrogen, and phosphorus than Red Leptosol (RedS). The most outstanding difference in the bacterial community structure between BlaS and RedS was that while in BlaS Actinobacteria was the most abundant phylum (43.7%), followed by Acidobacteria (26.9%) and Proteobacteria (23.6%), in RedS the bacterial community was strongly dominated by Acidobacteria (83%). Two fungal phyla were identified in both kinds of soil; Ascomycota, with 77% in BlaS and 56% in RedS, and Basidiomycota, with 22% in RedS and only 0.67% in BlaS. The most relevant difference between the two fungal communities was that excepting for Fusarium sp., all the species they had were different. Thus, in contrast with bacterial communities, where most of the major OTUs were present in both kinds of soil, fungal communities appeared to be unique to each kind of Leptosol.
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Schulz EC, Barabas O. Structure of an Escherichia coli Hfq:RNA complex at 0.97 Å resolution. Acta Crystallogr F Struct Biol Commun 2014; 70:1492-7. [PMID: 25372815 PMCID: PMC4231850 DOI: 10.1107/s2053230x14020044] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/05/2014] [Indexed: 12/28/2022] Open
Abstract
In bacteria, small RNAs (sRNAs) silence or activate target genes through base pairing with the mRNA, thereby modulating its translation. A central player in this process is the RNA chaperone Hfq, which facilitates the annealing of sRNAs with their target mRNAs. Hfq has two RNA-binding surfaces that recognize A-rich and U-rich sequences, and is believed to bind an sRNA-mRNA pair simultaneously. However, how Hfq promotes annealing remains unclear. Here, the crystal structure of Escherichia coli Hfq is presented in complex with U6-RNA bound to its proximal binding site at 0.97 Å resolution, revealing the Hfq-RNA interaction in exceptional detail.
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Affiliation(s)
- Eike C. Schulz
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Orsolya Barabas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
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Abstract
To adapt to stresses encountered in stationary phase, Gram-negative bacteria utilize the alternative sigma factor RpoS. However, some species lack RpoS; thus, it is unclear how stationary-phase adaptation is regulated in these organisms. Here we defined the growth-phase-dependent transcriptomes of Haemophilus ducreyi, which lacks an RpoS homolog. Compared to mid-log-phase organisms, cells harvested from the stationary phase upregulated genes encoding several virulence determinants and a homolog of hfq. Insertional inactivation of hfq altered the expression of ~16% of the H. ducreyi genes. Importantly, there were a significant overlap and an inverse correlation in the transcript levels of genes differentially expressed in the hfq inactivation mutant relative to its parent and the genes differentially expressed in stationary phase relative to mid-log phase in the parent. Inactivation of hfq downregulated genes in the flp-tad and lspB-lspA2 operons, which encode several virulence determinants. To comply with FDA guidelines for human inoculation experiments, an unmarked hfq deletion mutant was constructed and was fully attenuated for virulence in humans. Inactivation or deletion of hfq downregulated Flp1 and impaired the ability of H. ducreyi to form microcolonies, downregulated DsrA and rendered H. ducreyi serum susceptible, and downregulated LspB and LspA2, which allow H. ducreyi to resist phagocytosis. We propose that, in the absence of an RpoS homolog, Hfq serves as a major contributor of H. ducreyi stationary-phase and virulence gene regulation. The contribution of Hfq to stationary-phase gene regulation may have broad implications for other organisms that lack an RpoS homolog. Pathogenic bacteria encounter a wide range of stresses in their hosts, including nutrient limitation; the ability to sense and respond to such stresses is crucial for bacterial pathogens to successfully establish an infection. Gram-negative bacteria frequently utilize the alternative sigma factor RpoS to adapt to stresses and stationary phase. However, homologs of RpoS are absent in some bacterial pathogens, including Haemophilus ducreyi, which causes chancroid and facilitates the acquisition and transmission of HIV-1. Here, we provide evidence that, in the absence of an RpoS homolog, Hfq serves as a major contributor of stationary-phase gene regulation and that Hfq is required for H. ducreyi to infect humans. To our knowledge, this is the first study describing Hfq as a major contributor of stationary-phase gene regulation in bacteria and the requirement of Hfq for the virulence of a bacterial pathogen in humans.
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