Molecular signatures (conserved indels) in protein sequences that are specific for the order Pasteurellales and distinguish two of its main clades

2011 ◽  
Vol 101 (1) ◽  
pp. 105-124 ◽  
Author(s):  
Hafiz Sohail Naushad ◽  
Radhey S. Gupta
Keyword(s):  
Protein Sequences ◽  
Molecular Signatures ◽  
Conserved Indels

scholarly journals Phylogenomic analyses and molecular signatures for the class Halobacteria and its two major clades: a proposal for division of the class Halobacteria into an emended order Halobacteriales and two new orders, Haloferacales ord. nov. and Natrialbales ord. nov., containing the novel families Haloferacaceae fam. nov. and Natrialbaceae fam. nov.

2015 ◽  
Vol 65 (Pt_3) ◽  
pp. 1050-1069 ◽  
Author(s):  
Radhey S. Gupta ◽  
Sohail Naushad ◽  
Sheridan Baker
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Protein Sequences ◽  
Rrna Gene ◽  
Molecular Signatures ◽  
The Novel ◽  
Gene Trees ◽  
Content Type ◽  
Link Type

The Halobacteria constitute one of the largest groups within the Archaea . The hierarchical relationship among members of this large class, which comprises a single order and a single family, has proven difficult to determine based upon 16S rRNA gene trees and morphological and physiological characteristics. This work reports detailed phylogenetic and comparative genomic studies on >100 halobacterial (haloarchaeal) genomes containing representatives from 30 genera to investigate their evolutionary relationships. In phylogenetic trees reconstructed on the basis of 32 conserved proteins, using both neighbour-joining and maximum-likelihood methods, two major clades (clades A and B) encompassing nearly two-thirds of the sequenced haloarchaeal species were strongly supported. Clades grouping the same species/genera were also supported by the 16S rRNA gene trees and trees for several individual highly conserved proteins (RpoC, EF-Tu, UvrD, GyrA, EF-2/EF-G). In parallel, our comparative analyses of protein sequences from haloarchaeal genomes have identified numerous discrete molecular markers in the form of conserved signature indels (CSI) in protein sequences and conserved signature proteins (CSPs) that are found uniquely in specific groups of haloarchaea. Thirteen CSIs in proteins involved in diverse functions and 68 CSPs that are uniquely present in all or most genome-sequenced haloarchaea provide novel molecular means for distinguishing members of the class Halobacteria from all other prokaryotes. The members of clade A are distinguished from all other haloarchaea by the unique shared presence of two CSIs in the ribose operon protein and small GTP-binding protein and eight CSPs that are found specifically in members of this clade. Likewise, four CSIs in different proteins and five other CSPs are present uniquely in members of clade B and distinguish them from all other haloarchaea. Based upon their specific clustering in phylogenetic trees for different gene/protein sequences and the unique shared presence of large numbers of molecular signatures, members of clades A and B are indicated to be distinct from all other haloarchaea because of their uniquely shared evolutionary histories. Based upon these results, it is proposed that clades A and B be recognized as two new orders, Natrialbales ord. nov. and Haloferacales ord. nov., within the class Halobacteria , containing the novel families Natrialbaceae fam. nov. and Haloferacaceae fam. nov. Other members of the class Halobacteria that are not members of these two orders will remain part of the emended order Halobacteriales in an emended family Halobacteriaceae .

scholarly journals Molecular signatures of Janthinobacterium lividum from Trinidad support high potential for crude oil metabolism

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amanda C. Ramdass ◽  
Sephra N. Rampersad
Keyword(s):  
16S Rrna ◽  
Bacterial Species ◽  
Protein Sequences ◽  
Phylogenetic Inference ◽  
Amino Acid Sequences ◽  
Molecular Signatures ◽  
Bioinformatics Analyses ◽  
Specific Level ◽  
Synonymous Substitutions ◽  
Janthinobacterium Lividum

Abstract Background Janthinobacterium lividum is considered to be a psychrotrophic bacterial species. For the first time in the literature, J. lividum strains were isolated from Trinidad presenting with atypical features - hydrocarbonoclastic and able to survive in a tropical environment. Methods Identification of the Trinidad strains was carried out through 16S rRNA phylogenetic analysis. Gene-specific primers were designed to target the VioA which encodes violacein pigment and the EstA/B gene which encodes secreted extracellular lipase. Bioinformatics analyses were carried out on the nucleotide and amino acid sequences of VioA and EstA/B genes of the Trinidad Janthinobacterium strains to assess functionality and phylogenetic relatedness to other Janthinobacterium sequences specifically and more broadly, to other members of the Oxalobacteraceae family of betaproteobacteria. Results 16S rRNA confirmed the identity of the Trinidad strains as J. lividum and resolved three of the Trinidad strains at the intra-specific level. Typical motility patterns of this species were recorded. VioAp sequences were highly conserved, however, synonymous substitutions located outside of the critical sites for enzyme function were detected for the Trinidad strains. Comparisons with PDB 6g2p model from aa231 to aa406 further indicated no functional disruption of the VioA gene of the Trinidad strains. Phylogeny of the VioA protein sequences inferred placement of all J. lividum taxa into a highly supported species-specific clade (bs = 98%). EstA/Bp sequences were highly conserved, however, synonymous substitutions were detected that were unique to the Trinidad strains. Phylogenetic inference positioned the Trinidad consensus VioA and EstA protein sequences in a clearly distinct branch. Conclusions The findings showed that the primary sequence of VioAp and EstA/Bp were unique to the Trinidad strains and these molecular signatures were reflected in phylogenetic inference. Our results supported chemotaxis, possible elective inactivation of VioA gene expression and secreted lipase activity as survival mechanisms of the Trinidad strains in petrogenic conditions.

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