Dataset Information

Comparative analysis of RNA regulatory elements of amino acid metabolism genes in Actinobacteria.

ABSTRACT: BACKGROUND: Formation of alternative structures in mRNA in response to external stimuli, either direct or mediated by proteins or other RNAs, is a major mechanism of regulation of gene expression in bacteria. This mechanism has been studied in detail using experimental and computational approaches in proteobacteria and Firmicutes, but not in other groups of bacteria. RESULTS: Comparative analysis of amino acid biosynthesis operons in Actinobacteria resulted in identification of conserved regions upstream of several operons. Classical attenuators were predicted upstream of trp operons in Corynebacterium spp. and Streptomyces spp., and trpS and leuS genes in some Streptomyces spp. Candidate leader peptides with terminators were observed upstream of ilvB genes in Corynebacterium spp., Mycobacterium spp. and Streptomyces spp. Candidate leader peptides without obvious terminators were found upstream of cys operons in Mycobacterium spp. and several other species. A conserved pseudoknot (named LEU element) was identified upstream of leuA operons in most Actinobacteria. Finally, T-boxes likely involved in the regulation of translation initiation were observed upstream of ileS genes from several Actinobacteria. CONCLUSION: The metabolism of tryptophan, cysteine and leucine in Actinobacteria seems to be regulated on the RNA level. In some cases the mechanism is classical attenuation, but in many cases some components of attenuators are missing. The most interesting case seems to be the leuA operon preceded by the LEU element that may fold into a conserved pseudoknot or an alternative structure. A LEU element has been observed in a transposase gene from Bifidobacterium longum, but it is not conserved in genes encoding closely related transposases despite a very high level of protein similarity. One possibility is that the regulatory region of the leuA has been co-opted from some element involved in transposition. Analysis of phylogenetic patterns allowed for identification of ML1624 of M. leprae and its orthologs as the candidate regulatory proteins that may bind to the LEU element. T-boxes upstream of the ileS genes are unusual, as their regulatory mechanism seems to be inhibition of translation initiation via a hairpin sequestering the Shine-Dalgarno box.

SUBMITTER: Seliverstov AV

PROVIDER: S-EPMC1262725 | biostudies-literature | 2005

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Comparative analysis of RNA regulatory elements of amino acid metabolism genes in Actinobacteria.

Seliverstov Alexander V AV Putzer Harald H Gelfand Mikhail S MS Lyubetsky Vassily A VA

BMC microbiology 20051003

<h4>Background</h4>Formation of alternative structures in mRNA in response to external stimuli, either direct or mediated by proteins or other RNAs, is a major mechanism of regulation of gene expression in bacteria. This mechanism has been studied in detail using experimental and computational approaches in proteobacteria and Firmicutes, but not in other groups of bacteria.<h4>Results</h4>Comparative analysis of amino acid biosynthesis operons in Actinobacteria resulted in identification of cons ...[more]

PMID: 16202131

Similar Datasets

Project description:A targeted customized sequencing of genes implicated in autosomal recessive polycystic kidney disease (ARPKD) phenotype was performed to identify candidate variants using the Ion torrent PGM next-generation sequencing. The results identified four potential pathogenic variants in PKHD1 gene [c.4870C > T, p.(Arg1624Trp), c.5725C > T, p.(Arg1909Trp), c.1736C > T, p.(Thr579Met) and c.10628T > G, p.(Leu3543Trp)] among 12 out of 18 samples. However, one variant c.4870C > T, p.(Arg1624Trp) was common among eight patients. Some patient samples also showed few variants in autosomal dominant polycystic kidney disease (ADPKD) disease causing genes PKD1 and PKD2 such as c.12433G > A, p.(Val4145Ile) and c.1445T > G, p.(Phe482Cys), respectively. All causative variants were validated by capillary sequencing and confirmed the presence of a novel homozygous variant c.10628T > G, p.(Leu3543Trp) in a male proband. We have recently published the results of these studies (Edrees et al., 2016). Here we report for the first time the effect of the common mutation p.(Arg1624Trp) found in eight samples on the protein structure and function due to the specific amino acid changes of PKHD1 protein using molecular dynamics simulations. The computational approaches provide tool predict the phenotypic effect of variant on the structure and function of the altered protein. The structural analysis with the common mutation p.(Arg1624Trp) in the native and mutant modeled protein were also studied for solvent accessibility, secondary structure and stabilizing residues to find out the stability of the protein between wild type and mutant forms. Furthermore, comparative genomics and evolutionary analyses of variants observed in PKHD1, PKD1, and PKD2 genes were also performed in some mammalian species including human to understand the complexity of genomes among closely related mammalian species. Taken together, the results revealed that the evolutionary comparative analyses and characterization of PKHD1, PKD1, and PKD2 genes among various related and unrelated mammalian species will provide important insights into their evolutionary process and understanding for further disease characterization and management.

Project description:Iron is a critical nutrient for most microbial pathogens, and the immune system exploits this requirement by sequestering iron. The opportunistic pathogen Pseudomonas aeruginosa exhibits a high requirement for iron yet an exquisite ability to overcome iron deprivation during infection. Upon iron starvation, P. aeruginosa induces the expression of several high-affinity iron acquisition systems, as well as the PrrF small regulatory RNAs (sRNAs) that mediate an iron-sparing response. Here, we used liquid chromatography-tandem mass spectrometry to conduct proteomics of the iron starvation response of P. aeruginosa Iron starvation increased levels of multiple proteins involved in amino acid catabolism, providing the capacity for iron-independent entry of carbons into the tricarboxylic acid (TCA) cycle. Proteins involved in sulfur assimilation and cysteine biosynthesis were reduced upon iron starvation, while proteins involved in iron-sulfur cluster biogenesis were increased, highlighting the central role of iron in P. aeruginosa metabolism. Iron starvation also resulted in changes in the expression of several zinc-responsive proteins and increased levels of twitching motility proteins. Subsequent analyses provided evidence for the regulation of many of these proteins via posttranscriptional regulatory events, some of which are dependent upon the PrrF sRNAs. Moreover, we showed that iron-regulated twitching motility is partially dependent upon the prrF locus, highlighting a novel link between the PrrF sRNAs and motility. These findings add to the known impacts of iron starvation in P. aeruginosa and outline potentially novel roles for the PrrF sRNAs in iron homeostasis and pathogenesis.IMPORTANCE Iron is central for growth and metabolism of almost all microbial pathogens, and as such, this element is sequestered by the host innate immune system to restrict microbial growth. Here, we used label-free proteomics to investigate the Pseudomonas aeruginosa iron starvation response, revealing a broad landscape of metabolic and metal homeostasis changes that have not previously been described. We further provide evidence that many of these processes, including twitching motility, are regulated through the iron-responsive PrrF small regulatory RNAs. As such, this study demonstrates the power of proteomics for defining stress responses of microbial pathogens.

Project description:The control of amino acid synthesis and transport in bacteria has been well-investigated at the transcriptional level. The discovery of a small Hfq-dependent regulatory RNA, GcvB, added another layer of gene expression control at the post-transcriptional level. GcvB RNA has been shown to directly regulate multiple ABC transporters for amino acids in E. coli and Salmonella using a highly conserved G/U-rich domain, R1. To identify additional GcvB targets, we have combined a sRNA pulse-expression and microarray analysis of whole transcriptome changes with biocomputational target searches for C/A- rich target sites in Salmonella. Moreover, we have included GcvB mutant RNAs in our microarray approach providing a new target search approach by inactivating conserved domains or target interaction sites. This dual approach revealed further amino acid transporters and, in addition, genes involved in amino acid metabolism as consensus R1-dependent GcvB targets. Moreover, GcvB RNA seems to bind with at least two binding sites to an R1-independent target, the glycine transporter cycA. Using GFP reporter gene fusions we have now validated 21 GcvB targets which is best to our knowledge with ~1% of all Salmonella protein coding genes, the largest bacterial sRNA-controlled regulon. Intriguingly, GcvB rewires many primary control circuits and, thus, constitutes an important metabolic knot. To predict direct GcvB targets with better confidence, we expanded the sRNA pulse-expression approach to assay effects of several versions of GcvB sRNA. We cloned GcvB wild-type and mutants RNAs deleted for the conserved regions R1 or R2 (Fig. 1A) under control of an arabinose-inducible PBAD promoter, yielding plasmid pBAD-GcvB (pKP1-1), pBAD-GcvB delta R1 (pKP2-6) and pBAD-GcvB delta R2 (pKP30-1). For confirmation of inducible expression, Salmonella wild-type carrying pBAD control vector (pKP8-35), and Salmonella ΔgcvB carrying either control vector (Ctr) or the above GcvB expression plasmids were grown to mid-exponential phase (OD600 of 1) and treated with L-arabinose for up to 15 min. We used whole-genome S. typhimurium microarrays to determine relative mRNA expression changes at 10 min of induction, comparing the mRNA profiles of the pBAD-GcvB, pBAD-GcvB delta R1 or pBAD-GcvB delta R2 strains to that of the delta gcvB deletion mutant strain carrying the control vector. Microarrays used in this study were produced by in-situ synthesis as 8x15k multipack format from Agilent Technologies. Each microarray comprises 13268 60-mer S. typhimurium strain SL1344 specific oligonucleotides supplemented with 319 60-mer S. enterica subsp. serovar Typhimurium 14028S specific oligonucleotides, 360 60-mer S. typhimurium LT2 specific oligonucleotides and 360 60-mer oligonucleotides specific for 149 Salmonella sRNAs. The experimental design involves the use of Salmonella enterica serovar Typhimurium genomic DNA as the co-hybridized control for one channel on all microarrays. Two independent biological eperiments were analyzed.

Dataset Information

Comparative analysis of RNA regulatory elements of amino acid metabolism genes in Actinobacteria.

Publications

Comparative analysis of RNA regulatory elements of amino acid metabolism genes in Actinobacteria.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets