Data on genome assembly and annotation of Marinobacter sp. strain CA1 isolated from indigenous diatom found in whiteleg shrimp pond in Malaysia.

Marinobacter is a genus belonging to the class Gammaproteobacteria and the family Alteromonadaceae. This genus is a Gram-negative bacterium which can be found in a wide range of marine and saline water environments. Here, we present the genome sequence of Marinobacter sp. strain CA1 that was isolated from the indigenous diatom found in the whiteleg shrimp, Penaeus vannamei (Bonne 1931) pond in Malaysia. Genome sequencing was done using Pacbio and Illumina sequencing platforms. De novo hybrid assembly based on Pacbio long reads and high quality Illumina short reads yielded a complete circular chromosome with 4.7 M base pair (bp) in size. This genome was submitted to Genbank, NCBI database and can be accessed under accession number: NZ_CP071785 and the BioProject acession number PRJNA710741. This data could be useful for other studies on microalgae and bacteria interaction, and comparative genomics analysis of other Marinobacter species.

Identification of sRNA mediated responses to nutrient depletion in Burkholderia pseudomallei.

The Burkholderia genus includes many species that are known to survive in diverse environmental conditions including low nutrient environments. One species, Burkholderia pseudomallei is a versatile pathogen that can survive in a wide range of hosts and environmental conditions. In this study, we investigated how a nutrient depleted growth environment evokes sRNA mediated responses by B. pseudomallei. Computationally predicted B. pseudomallei D286 sRNAs were mapped to RNA-sequencing data for cultures grown under two conditions: (1) BHIB as a nutrient rich media reference environment and (2) M9 media as a nutrient depleted stress environment. The sRNAs were further selected to identify potentially cis-encoded systems by investigating their possible interactions with their flanking genes. The mappings of predicted sRNA genes and interactions analysis to their flanking genes identified 12 sRNA candidates that may possibly have cis-acting regulatory roles that are associated to a nutrient depleted growth environment. Our approach can be used for identifying novel sRNA genes and their possible role as cis-mediated regulatory systems.

3D modelling of the pathogenic Leptospira protein LipL32: A bioinformatics approach.

Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira species (Leptospiraceae). LipL32 is an abundant lipoprotein from the outer membrane proteins (OMPs) group, highly conserved among pathogenic and intermediate Leptospira species. Several studies used LipL32 as a specific gene to identify the presence of leptospires. This research was aimed to study the characteristics of LipL32 protein gene code, to fill the knowledge gap concerning the most appropriate gene that can be used as antigen to detect the Leptospira. Here, we investigated the features of LipL32 in fourteen Leptospira pathogenic strains based on comparative analyses of their primary, secondary structures and 3D modeling using a bioinformatics approach. Furthermore, the physicochemical properties of LipL32 in different strains were studied, shedding light on the identity of signal peptides, as well as on the secondary and tertiary structure of the LipL32 protein, supported by 3D modelling assays. The results showed that the LipL32 gene was present in all the fourteen pathogenic Leptospira strains used in this study, with limited diversity in terms of sequence conservation, hydrophobic group, hydrophilic group and number of turns (random coil). Overall, these results add basic knowledge to the characteristics of LipL32 protein, contributing to the identification of potential antigen candidates in future research, in order to ensure prompt and reliable detection of pathogenic Leptospira species.

Phylogenetic analyses uncover a novel clade of transferrin in nonmammalian vertebrates.

Transferrin is a protein super-family involved in iron transport, a central process in cellular homeostasis. Throughout the evolution of vertebrates, transferrin members have diversified into distinct subfamilies including serotransferrin, ovotransferrin, lactoferrin, melanotransferrin, the inhibitor of carbonic anhydrase, pacifastin, and the major yolk protein in sea urchin. Previous phylogenetic analyses have established the branching order of the diverse transferrin subfamilies but were mostly focused on the transferrin repertoire present in mammals. Here, we conduct a comprehensive phylogenetic analysis of transferrin protein sequences in sequenced vertebrates, placing a special focus on the less-studied nonmammalian vertebrates. Our analyses uncover a novel transferrin clade present across fish, sauropsid, and amphibian genomes but strikingly absent from mammals. Our reconstructed scenario implies that this novel class emerged through a duplication event at the vertebrate ancestor, and that it was subsequently lost in the lineage leading to mammals. We detect footprints of accelerated evolution following the duplication event, which suggest positive selection and early functional divergence of this novel clade. Interestingly, the loss of this novel class of transferrin in mammals coincided with the divergence by duplication of lactoferrin and serotransferrin in this lineage. Altogether, our results provide novel insights on the evolution of iron-binding proteins in the various vertebrate groups.

Characterization of the functional domain of ß2-microglobulin from the Asian seabass, Lates calcarifer.

BACKGROUND: ß2-Microglobulin (ß(2)M) is the light chain of major histocompatibility class I (MHC I) that binds non-covalently with the α heavy chain. Both proteins attach to the antigen peptide, presenting a complex to the T cell to be destroyed via the immune mechanism. METHODOLOGY/PRINCIPAL FINDINGS: In this study, a cDNA sequence encoding ß(2)M in the Asian seabass (Lates calcarifer) was identified and analyzed using in silico approaches to predict and characterize its functional domain. The ß(2)M cDNA contains an open reading frame (ORF) of 351 bases with a coding capacity of 116 amino acids. A large portion of the protein consists of the IG constant domain (IGc1), similar to ß(2)M sequences from other species studied thus far. Alignment of the IGc1 domains of ß(2)M from L. calcarifer and other species shows a high degree of overall conservation. Seven amino acids were found to be conserved across taxa whereas conservation between L. calcarifer and other fish species was restricted to 14 amino acids at identical conserved positions. CONCLUSION/SIGNIFICANCE: As the L. calcarifer ß(2)M protein analyzed in this study contains a functional domain similar to that of ß(2)M proteins in other species, it can be postulated that the ß(2)M proteins from L. calcarifer and other organisms are derived from a common ancestor and thus have a similar immune function. Interestingly, fish ß(2)M genes could also be classified according to the ecological habitat of the species, i.e. whether it is from a freshwater, marine or euryhaline environment.