scholarly journals Complete WO Phage Sequences Reveal Their Dynamic Evolutionary Trajectories and Putative Functional Elements Required for Integration into the Wolbachia Genome

2009 ◽  
Vol 75 (17) ◽  
pp. 5676-5686 ◽  
Author(s):  
Kohjiro Tanaka ◽  
Seiichi Furukawa ◽  
Naruo Nikoh ◽  
Tetsuhiko Sasaki ◽  
Takema Fukatsu
Keyword(s):  
Genetic Transformation ◽  
Protein Interactions ◽  
Phylogenetic Analyses ◽  
Attachment Site ◽  
Host Bacterium ◽  
Sequence Motifs ◽  
Integrase Gene ◽  
Bacterial Phyla ◽  
Genetic Elements ◽  
Evolutionary Trajectories

ABSTRACT Wolbachia endosymbionts are ubiquitously found in diverse insects including many medical and hygienic pests, causing a variety of reproductive phenotypes, such as cytoplasmic incompatibility, and thereby efficiently spreading in host insect populations. Recently, Wolbachia-mediated approaches to pest control and management have been proposed, but the application of these approaches has been hindered by the lack of genetic transformation techniques for symbiotic bacteria. Here, we report the genome and structure of active bacteriophages from a Wolbachia endosymbiont. From the Wolbachia strain wCauB infecting the moth Ephestia kuehniella two closely related WO prophages, WOcauB2 of 43,016 bp with 47 open reading frames (ORFs) and WOcauB3 of 45,078 bp with 46 ORFs, were characterized. In each of the prophage genomes, an integrase gene and an attachment site core sequence were identified, which are putatively involved in integration and excision of the mobile genetic elements. The 3′ region of the prophages encoded genes with sequence motifs related to bacterial virulence and protein-protein interactions, which might represent effector molecules that affect cellular processes and functions of their host bacterium and/or insect. Database searches and phylogenetic analyses revealed that the prophage genes have experienced dynamic evolutionary trajectories. Genes similar to the prophage genes were found across divergent bacterial phyla, highlighting the active and mobile nature of the genetic elements. We suggest that the active WO prophage genomes and their constituent sequence elements would provide a clue to development of a genetic transformation vector for Wolbachia endosymbionts.

scholarly journals Analysis of the Genetic Switch and Replication Region of a P335-Type Bacteriophage with an Obligate Lytic Lifestyle onLactococcus lactis

2001 ◽  
Vol 67 (3) ◽  
pp. 1128-1139 ◽  
Author(s):  
Søren M. Madsen ◽  
David Mills ◽  
Gordana Djordjevic ◽  
Hans Israelsen ◽  
Todd R. Klaenhammer
Keyword(s):  
Gene Expression ◽  
Attachment Site ◽  
Streptococcus Thermophilus ◽  
Regulatory Elements ◽  
Lytic Phage ◽  
Genetic Switch ◽  
Integrase Gene ◽  
Replication Module ◽  
Gene Homologue ◽  
I Gene

ABSTRACT The DNA sequence of the replication module, part of the lysis module, and remnants of a lysogenic module from the lytic P335 species lactococcal bacteriophage φ31 was determined, and its regulatory elements were investigated. The identification of a characteristic genetic switch including two divergent promoters and two cognate repressor genes strongly indicates that φ31 was derived from a temperate bacteriophage. Regulation of the two early promoters was analyzed by primer extension and transcriptional promoter fusions to a lacLMreporter. The regulatory behavior of the promoter region differed significantly from the genetic responses of temperate Lactococcus lactis phages. Thecro gene homologue regulates its own production and is an efficient repressor of cI gene expression. No detectablecI gene expression could be measured in the presence ofcro. cI gene expression in the absence ofcro exerted minor influences on the regulation of the two promoters within the genetic switch. Homology comparisons revealed a replication module which is most likely expressed from the promoter located upstream of the cro gene homologue. The replication module encoded genes with strong homology to helicases and primases found in several Streptococcus thermophilus phages. Downstream of the primase homologue, an AT-rich noncoding origin region was identified. The characteristics and location of this region and its ability to reduce the efficiency of plaquing of φ31 106-fold when present at high copy number in trans provide evidence for identification of the phage origin of replication. Phage φ31 is an obligately lytic phage that was isolated from commercial dairy fermentation environments. Neither a phage attachment site nor an integrase gene, required to establish lysogeny, was identified, explaining its lytic lifestyle and suggesting its origin from a temperate phage ancestor. Several regions showing extensive DNA and protein homologies to different temperate phages ofLactococcus, Lactobacillus, andStreptococcus were also discovered, indicating the likely exchange of DNA cassettes through horizontal gene transfer in the dynamic ecological environment of dairy fermentations.

Metallocluster transactions: dynamic protein interactions guide the biosynthesis of Fe–S clusters in bacteria

2018 ◽  
Vol 46 (6) ◽  
pp. 1593-1603 ◽  
Author(s):  
Chenkang Zheng ◽  
Patricia C. Dos Santos
Keyword(s):  
Protein Interactions ◽  
Protein Complexes ◽  
Specific Protein ◽  
Biological Synthesis ◽  
Cluster Assembly ◽  
Sequence Motifs ◽  
Protein Protein Interactions ◽  
Cysteine Desulfurase ◽  
Wide Range ◽  
Domains Of Life

Iron–sulfur (Fe–S) clusters are ubiquitous cofactors present in all domains of life. The chemistries catalyzed by these inorganic cofactors are diverse and their associated enzymes are involved in many cellular processes. Despite the wide range of structures reported for Fe–S clusters inserted into proteins, the biological synthesis of all Fe–S clusters starts with the assembly of simple units of 2Fe–2S and 4Fe–4S clusters. Several systems have been associated with the formation of Fe–S clusters in bacteria with varying phylogenetic origins and number of biosynthetic and regulatory components. All systems, however, construct Fe–S clusters through a similar biosynthetic scheme involving three main steps: (1) sulfur activation by a cysteine desulfurase, (2) cluster assembly by a scaffold protein, and (3) guided delivery of Fe–S units to either final acceptors or biosynthetic enzymes involved in the formation of complex metalloclusters. Another unifying feature on the biological formation of Fe–S clusters in bacteria is that these systems are tightly regulated by a network of protein interactions. Thus, the formation of transient protein complexes among biosynthetic components allows for the direct transfer of reactive sulfur and Fe–S intermediates preventing oxygen damage and reactions with non-physiological targets. Recent studies revealed the importance of reciprocal signature sequence motifs that enable specific protein–protein interactions and consequently guide the transactions between physiological donors and acceptors. Such findings provide insights into strategies used by bacteria to regulate the flow of reactive intermediates and provide protein barcodes to uncover yet-unidentified cellular components involved in Fe–S metabolism.

scholarly journals Expanding magnetic organelle biogenesis in the domain Bacteria

Microbiome ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Wei Lin ◽  
Wensi Zhang ◽  
Greig A. Paterson ◽  
Qiyun Zhu ◽  
Xiang Zhao ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Biological Significance ◽  
Gene Clusters ◽  
Magnetic Sensors ◽  
Evolutionary Origin ◽  
Phylogenomic Analysis ◽  
Organelle Biogenesis ◽  
Taxonomic Distribution ◽  
Origin And Evolution ◽  
Bacterial Phyla

Abstract Background The discovery of membrane-enclosed, metabolically functional organelles in Bacteria has transformed our understanding of the subcellular complexity of prokaryotic cells. Biomineralization of magnetic nanoparticles within magnetosomes by magnetotactic bacteria (MTB) is a fascinating example of prokaryotic organelles. Magnetosomes, as nano-sized magnetic sensors in MTB, facilitate cell navigation along the local geomagnetic field, a behaviour referred to as magnetotaxis or microbial magnetoreception. Recent discovery of novel MTB outside the traditionally recognized taxonomic lineages suggests that MTB diversity across the domain Bacteria are considerably underestimated, which limits understanding of the taxonomic distribution and evolutionary origin of magnetosome organelle biogenesis. Results Here, we perform the most comprehensive metagenomic analysis available of MTB communities and reconstruct metagenome-assembled MTB genomes from diverse ecosystems. Discovery of MTB in acidic peatland soils suggests widespread MTB occurrence in waterlogged soils in addition to subaqueous sediments and water bodies. A total of 168 MTB draft genomes have been reconstructed, which represent nearly a 3-fold increase over the number currently available and more than double the known MTB species at the genome level. Phylogenomic analysis reveals that these genomes belong to 13 Bacterial phyla, six of which were previously not known to include MTB. These findings indicate a much wider taxonomic distribution of magnetosome organelle biogenesis across the domain Bacteria than previously thought. Comparative genome analysis reveals a vast diversity of magnetosome gene clusters involved in magnetosomal biogenesis in terms of gene content and synteny residing in distinct taxonomic lineages. Phylogenetic analyses of core magnetosome proteins in this largest available and taxonomically diverse dataset support an unexpectedly early evolutionary origin of magnetosome biomineralization, likely ancestral to the origin of the domain Bacteria. Conclusions These findings expand the taxonomic and phylogenetic diversity of MTB across the domain Bacteria and shed new light on the origin and evolution of microbial magnetoreception. Potential biogenesis of the magnetosome organelle in the close descendants of the last bacterial common ancestor has important implications for our understanding of the evolutionary history of bacterial cellular complexity and emphasizes the biological significance of the magnetosome organelle.

scholarly journals Heterogeneity of Tn5253-Like Composite Elements in ClinicalStreptococcus pneumoniaeIsolates

2011 ◽  
Vol 55 (4) ◽  
pp. 1453-1459 ◽  
Author(s):  
Marina Mingoia ◽  
Emily Tili ◽  
Esther Manso ◽  
Pietro E. Varaldo ◽  
Maria Pia Montanari
Keyword(s):  
Tetracycline Resistance ◽  
Erythromycin Resistance ◽  
Integrase Gene ◽  
Chloramphenicol Resistance ◽  
Site Specific ◽  
Considerable Heterogeneity ◽  
Genetic Elements ◽  
Conjugative Transposons ◽  
Composite Element ◽  
Cell Genome

ABSTRACTSeveral drug resistances inStreptococcus pneumoniaeare associated with mobile genetic elements, which are loosely subdivided into a group of smaller (18- to 27-kb) and a group of larger (>50-kb) elements. While the elements of the former group, which typically carry the tetracycline resistance determinanttet(M) and whose prototype is Tn916(18 kb), have been studied extensively, the larger elements, whose prototype is Tn5253(∼65.5 kb), are not as well explored. Tn5253is a composite structure consisting of two independent conjugative transposons, Tn5251(which is virtually identical to Tn916) and Tn5252(∼47.5 kb), with the former inserted into the latter. Tn5252, which so far has only partially been sequenced, carries an integrase gene, driving its site-specific insertion into the host cell genome, and the chloramphenicol resistancecatpC194determinant. This study investigated 20 clinical isolates ofS. pneumoniae, which were selected on the basis ofcatpC194-mediated chloramphenicol resistance. All 20 isolates harbored a Tn5253-like element. The composite elements (some of which have been completely sequenced) demonstrated considerable heterogeneity that stemmed from a dual variability: in the Tn5252-like element, due primarily to differences in the integrase gene but also to differences in cargo genes and in the overall genetic organization, and in the Tn916-like element, with the possible involvement, besides Tn916, of a number of Tn916family pneumococcal elements carrying different erythromycin resistance genes. In mating experiments, only one composite element, containing a less typical Tn916family element, appeared to be nonmobile. Being part of a Tn5253-like composite element may confer on some Tn916-like transposons, which are apparently nontransferable as independent genetic elements, the ability to be mobilized.

scholarly journals Novelty and Uniqueness Patterns of Rare Members of the Soil Biosphere

2008 ◽  
Vol 74 (17) ◽  
pp. 5422-5428 ◽  
Author(s):  
Mostafa S. Elshahed ◽  
Noha H. Youssef ◽  
Anne M. Spain ◽  
Cody Sheik ◽  
Fares Z. Najar ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Bacterial Species ◽  
Rrna Gene ◽  
Tall Grass ◽  
Data Set ◽  
Bacterial Phyla ◽  
Rare Biosphere ◽  
Soil Bacterial ◽  
Close Relatives ◽  
Taxonomic Groups

ABSTRACT Soil bacterial communities typically exhibit a distribution pattern in which most bacterial species are present in low abundance. Due to the relatively small size of most culture-independent sequencing surveys, a detailed phylogenetic analysis of rare members of the community is lacking. To gain access to the rarely sampled soil biosphere, we analyzed a data set of 13,001 near-full-length 16S rRNA gene clones derived from an undisturbed tall grass prairie soil in central Oklahoma. Rare members of the soil bacterial community (empirically defined at two different abundance cutoffs) represented 18.1 to 37.1% of the total number of clones in the data set and were, on average, less similar to their closest relatives in public databases when compared to more abundant members of the community. Detailed phylogenetic analyses indicated that members of the soil rare biosphere either belonged to novel bacterial lineages (members of five novel bacterial phyla identified in the data set, as well as members of multiple novel lineages within previously described phyla or candidate phyla), to lineages that are prevalent in other environments but rarely encountered in soil, or were close relatives to more abundant taxa in the data set. While a fraction of the rare community was closely related to more abundant taxonomic groups in the data set, a significant portion of the rare biosphere represented evolutionarily distinct lineages at various taxonomic cutoffs. We reason that these novelty and uniqueness patterns provide clues regarding the origins and potential ecological roles of members of the soil's rare biosphere.

scholarly journals The PAX3 and 7 homeodomains have evolved unique determinants that influence DNA-binding, structure and communication with the paired domain

2019 ◽  
Author(s):  
Gareth N. Corry ◽  
Brian D. Sykes ◽  
D. Alan Underhill
Keyword(s):  
Dna Binding ◽  
Protein Interactions ◽  
Ternary Complex ◽  
Phylogenetic Analyses ◽  
Inhibitory Effect ◽  
Binding Assays ◽  
Paired Domain ◽  
Functional Diversification ◽  
H Nmr

ABSTRACTThe PAX (paired box) family is a collection of metazoan transcription factors defined by the paired domain, which confers sequence-specific DNA-binding. Ancestral PAX proteins also contained a homeodomain, which can communicate with the paired domain to modulate DNA-binding. In the present study, we sought to identify determinants of this functional interaction using the paralogous PAX3 and 7 proteins. First, we evaluated a group of heterologous paired domains and homeodomains for the ability to bind DNA cooperatively through formation of a ternary complex (paired domain:homeodomain:DNA). This revealed that capacity for ternary complex formation was unique to the PAX3 and 7 homeodomains and therefore not simply a consequence of DNA-binding. We also found PAX3 and 7 were distinguished by an extended region of conservation N-terminal to the homeodomain (NTE). Phylogenetic analyses established the NTE was restricted to PAX3/7 orthologs of segmented metazoans, indicating it arose in a bilaterian precursor prior to separation of deuterostomes and protostomes. In DNA-binding assays, presence of the NTE caused a decrease in monomeric binding by the PAX3 homeodomain that reflected a lack of secondary structure in 1D-1H-NMR. Nevertheless, this inhibitory effect could be overcome by homeodomain dimerization or cooperative binding with the paired domain, establishing that protein interactions could induce homeodomain folding in the presence of the NTE. Strikingly, the PAX7 counterpart did not impair homeodomain binding, revealing inherent differences that could account for its distinct target profile in vivo. Collectively, these findings identify critical determinants of PAX3 and 7 activity, which contribute to their functional diversification.

scholarly journals Dynamic changes in RNA–protein interactions and RNA secondary structure in mammalian erythropoiesis

2021 ◽  
Vol 4 (9) ◽  
pp. e202000659
Author(s):  
Mengge Shan ◽  
Xinjun Ji ◽  
Kevin Janssen ◽  
Ian M Silverman ◽  
Jesse Humenik ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Protein Interactions ◽  
Rna Secondary Structure ◽  
Rna Binding ◽  
Developmental Process ◽  
Global Analysis ◽  
Sequence Motifs ◽  
Rna Molecules ◽  
Interaction Sites ◽  
Rna Interaction

Two features of eukaryotic RNA molecules that regulate their post-transcriptional fates are RNA secondary structure and RNA-binding protein (RBP) interaction sites. However, a comprehensive global overview of the dynamic nature of these sequence features during erythropoiesis has never been obtained. Here, we use our ribonuclease-mediated structure and RBP-binding site mapping approach to reveal the global landscape of RNA secondary structure and RBP–RNA interaction sites and the dynamics of these features during this important developmental process. We identify dynamic patterns of RNA secondary structure and RBP binding throughout the process and determine a set of corresponding protein-bound sequence motifs along with their dynamic structural and RBP-binding contexts. Finally, using these dynamically bound sequences, we identify a number of RBPs that have known and putative key functions in post-transcriptional regulation during mammalian erythropoiesis. In total, this global analysis reveals new post-transcriptional regulators of mammalian blood cell development.

scholarly journals Sequence conservation, domain architectures, and phylogenetic distribution of the HD-GYP type c-di-GMP phosphodiesterases

2021 ◽  
Author(s):  
Michael Y. Galperin ◽  
Shan-Ho Chou
Keyword(s):  
Protein Interactions ◽  
Regulatory Protein ◽  
Second Messenger ◽  
Distribution Patterns ◽  
Distribution Functions ◽  
Amino Acid Residues ◽  
Sequence Motifs ◽  
Protein Protein Interactions ◽  
Conserved Sequence ◽  
Common Domain

The HD-GYP domain, named after two of its conserved sequence motifs, was first described in 1999 as a specialized version of the widespread HD phosphohydrolase domain that had additional highly conserved amino acid residues. Domain associations of HD-GYP indicated its involvement in bacterial signal transduction and distribution patterns of this domain suggested that it could serve as a hydrolase of the bacterial second messenger c-di-GMP, in addition to or instead of the EAL domain. Subsequent studies confirmed the ability of various HD-GYP domains to hydrolyze c-di-GMP to linear pGpG and/or GMP. Certain HD-GYP-containing proteins hydrolyze another second messenger, cGAMP, and some HD-GYP domains participate in regulatory protein-protein interactions. The recently solved structures of HD-GYP domains from four distinct organisms clarified the mechanisms of c-di-GMP binding and metal-assisted hydrolysis. However, the HD-GYP domain is poorly represented in public domain databases, which causes certain confusion about its phylogenic distribution, functions, and domain architectures. Here, we present a refined sequence model for the HD-GYP domain and describe the roles of its most conserved residues in metal and/or substrate binding. We also calculate the numbers of HD-GYPs encoded in various genomes and list the most common domain combinations involving HD-GYP, such as the RpfG (REC-HD-GYP), Bd1817 (DUF3391-HD-GYP), and PmGH (GAF-HD-GYP) protein families. We also provide the descriptions of six HD-GYP-associated domains, including four novel integral membrane sensor domains. This work is expected to stimulate studies of diverse HD-GYP-containing proteins, their N-terminal sensor domains, and the signals to which they respond.

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