Kloning Gen Coat Protein (CP) Carnation Mottle Virus (CarMV) pada Vektor Ekspresi [Cloning of Carnation Mottle Virus (CarMV) Coat Protein Gene into Expression Vector]

<p>Carnation mottle virus (CarMV) termasuk anggota genus Carmovirus dalam famili Tombusviridae. Virus ini banyak ditemukan menginfeksi tanaman anyelir di Jawa Barat dan menyebabkan gejala mottle. Sebagai langkah awal untuk memproduksi antiserum melalui teknik ekspresi gen CP perlu diklon pada vektor yang sesuai. Penelitian ini bertujuan mendapatkan klon CarMV yang berfungsi melalui kloning dan subkloning gen CP CarMV ke dalam vektor ekspresi yang sesuai. Penelitian dilakukan dalam beberapa tahap, yaitu ekstraksi RNA total dan amplifikasi cDNA CarMV dengan RT-PCR, menggunakan primer spesifik CarMVF dan CarMVR yang mengandung situs enzim restriksi XhoI dan BamHI, kloning dan subkloning DNA sisipan, serta konfirmasi transforman. Rekombinan gen sisipan CP CarMV dalam bakteri dikonfirmasi dengan koloni PCR. Gen CP CarMV berhasil dikloning ke dalam TA vektor pTZ57R/T dan disubkloning ke vektor ekspresi pET28a. Sekuen rekombinan CP CarMV berhasil dikonfirmasi melalui perunutan DNA. Penelitian lebih lanjut diperlukan untuk mendapatkan produksi antigen rekombinan yang melimpah pada bakteri ekspresi dan kondisi yang sesuai.</p><p><strong>Keywords</strong></p><p>Dianthus caryophillus L.; Carmovirus; Kloning; Subkloning; Bakteri ekspresi</p><p><strong>Abstract</strong></p><p>Carnation mottle virus (CarMV) is a type member of Carmovirus genus in family of Tombusvirus. The virus infects carnation plants in the centre area production of West Java and it cause mottle symptoms. The research aimed to obtain functional clone(s) of CarMV CP gene in suitable expression kloning vector. The research was carried out through several steps, namely total RNA extraction and amplification of cDNA of CP CarMV by RT-PCR using specific primer pairs CarMVF and CarMVR containing restriction enzyme sites XhoI and BamHI, respectively, TA cloning, and subcloning into expression vector pET28a and confirmation of recombinant plasmids by colony PCR. CarMV CP gen was successfully cloned into TA cloning vector pTZ57R/T and subcloned into vector pET28a, alsowere confirmed by DNA sequencing. Future experiment is necessary to be conducted to obtain abundance recombinant antigen production of CarMV CP in suitable expression condition and bacterial host.</p>

Biology and engineering of integrative and conjugative elements: Construction and analyses of hybrid ICEs reveal element functions that affect species-specific efficiencies

Integrative and conjugative elements (ICEs) are mobile genetic elements that reside in a bacterial host chromosome and are prominent drivers of bacterial evolution. They are also powerful tools for genetic analyses and engineering. Transfer of an ICE to a new host involves many steps, including excision from the chromosome, DNA processing and replication, transfer across the envelope of the donor and recipient, processing of the DNA, and eventual integration into the chromosome of the new host (now a stable transconjugant). Interactions between an ICE and its hosts throughout the life cycle likely influence the efficiencies of acquisition by new hosts. Here, we investigated how different functional modules of two ICEs, Tn916 and ICEBs1, affect the transfer efficiencies into different host bacteria. We constructed hybrid elements that utilize the high-efficiency regulatory and excision modules of ICEBs1 and the conjugation genes of Tn916. These elements produced more transconjugants than Tn916, likely due to increased excision frequencies. We also found that several Tn916 and ICEBs1 components can substitute for one other. Using B. subtilis donors and three Enterococcus species as recipients, we found that different hybrid elements were more readily acquired by some species than others, demonstrating species-specific interactions in steps of the ICE life cycle. This work demonstrates that hybrid elements utilizing the efficient regulatory functions of ICEBs1 can be built to enable efficient transfer into and engineering of a variety of other species.

Large Scale Discovery of Microbial Fibrillar Adhesins and Identification of Novel Adhesive Domain Families

Fibrillar adhesins are bacterial cell surface proteins that mediate interactions with host cells during colonisation and with other bacteria during biofilm formation. These proteins are characterised by a stalk that projects the adhesive domain closer to the binding target. Fibrillar adhesins evolve quickly and thus can be difficult to computationally identify, yet they represent an important component for understanding bacterial host interactions. To detect novel fibrillar adhesins we developed a random forest prediction approach based on common characteristics we identified for this protein class. We applied this approach to Firmicute and Actinobacterial proteomes, yielding over 4,000 confidently predicted fibrillar adhesins. To verify the approach we investigated predicted fibrillar adhesins that lacked a known adhesive domain. Based on these proteins, we identified 21 sequence clusters representing potential novel adhesive domains. We used AlphaFold to verify that 14 clusters showed structural similarity to known adhesive domains such as the TED domain. Overall our study has made a significant contribution to the number of known fibrillar adhesins and has enabled us to identify novel adhesive domain families involved in the bacterial pathogenesis.

Structural and Functional Analysis of SsaV Cytoplasmic Domain and Variable Linker States in the Context of the InvA-SsaV Chimeric Protein

Type III secretion system (T3SS) is a multicomponent nanomachine and a critical virulence factor for a wide range of Gram-negative bacterial pathogens. It can deliver numbers of effectors into the host cell to facilitate the bacterial host infection.

Surface proteomics and label-free quantification of Leptospira interrogans serovar Pomona

Leptospirosis is a re-emerging zoonosis with a global distribution. Surface-exposed outer membrane proteins (SE-OMPs) are crucial for bacterial–host interactions. SE-OMPs locate and expose their epitope on cell surface where is easily accessed by host molecules. This study aimed to screen for surface-exposed proteins and their abundance profile of pathogenic Leptospira interrogans serovar Pomona. Two complementary approaches, surface biotinylation and surface proteolytic shaving, followed by liquid chromatography tandem-mass spectrometry (LC-MS/MS) were employed to identify SE-OMPs of intact leptospires. For quantitative comparison, in-depth label-free analysis of SE-OMPs obtained from each method was performed using MaxQuant. The total number of proteins identified was 1,001 and 238 for surface biotinylation and proteinase K shaving, respectively. Among these, 39 were previously known SE-OMPs and 68 were predicted to be localized on the leptospiral surface. Based on MaxQuant analysis for relative quantification, six known SE-OMPs including EF- Tu, LipL21, LipL41, LipL46, Loa22, and OmpL36, and one predicted SE-OMPs, LipL71 were found in the 20 most abundant proteins, in which LipL41 was the highest abundant SE-OMP. Moreover, uncharacterized LIC14011 protein (LIP3228 ortholog in serovar Pomona) was identified as a novel predicted surface βb-OMP. High-abundance leptospiral SE-OMPs identified in this study may play roles in virulence and infection and are potential targets for development of vaccine or diagnostic tests for leptospirosis.

Phylogenetic Distribution of WhiB- and Lsr2-Type Regulators in Actinobacteriophage Genomes

Actinobacteriophages are viruses that infect bacterial species of the diverse phylum of Actinobacteria. Phages engage in a close relationship with their bacterial host.

Surface Glucan Structures in Aeromonas spp.

Aeromonas spp. are generally found in aquatic environments, although they have also been isolated from both fresh and processed food. These Gram-negative, rod-shaped bacteria are mostly infective to poikilothermic animals, although they are also considered opportunistic pathogens of both aquatic and terrestrial homeotherms, and some species have been associated with gastrointestinal and extraintestinal septicemic infections in humans. Among the different pathogenic factors associated with virulence, several cell-surface glucans have been shown to contribute to colonization and survival of Aeromonas pathogenic strains, in different hosts. Lipopolysaccharide (LPS), capsule and α-glucan structures, for instance, have been shown to play important roles in bacterial–host interactions related to pathogenesis, such as adherence, biofilm formation, or immune evasion. In addition, glycosylation of both polar and lateral flagella has been shown to be mandatory for flagella production and motility in different Aeromonas strains, and has also been associated with increased bacterial adhesion, biofilm formation, and induction of the host proinflammatory response. The main aspects of these structures are covered in this review.

Zymomonas mobilis ZM4 utilizes an acetaldehyde dehydrogenase to produce acetate

Zymomonas mobilis is a promising bacterial host for biofuel production but further improvement has been hindered because some aspects of its metabolism remain poorly understood. For example, one of the main byproducts generated by Z. mobilis is acetate but the pathway for acetate production is unknown. Acetaldehyde oxidation has been proposed as the major source of acetate and an acetaldehyde dehydrogenase was previously isolated from Z. mobilis via activity guided fractionation, but the corresponding gene has never been identified. We determined that the locus ZMO1754 (also known as ZMO_RS07890) encodes an NADP+-dependent acetaldehyde dehydrogenase that is responsible for acetate production by Z. mobilis. Deletion of this gene from the chromosome resulted in a growth defect in oxic conditions, suggesting that acetaldehyde detoxification is an important role of acetaldehyde dehydrogenase. The deletion strain also exhibited a near complete abolition of acetate production, both in typical laboratory conditions and during lignocellulosic hydrolysate fermentation. Our results show that ZMO1754 encodes the major acetaldehyde dehydrogenase in Z. mobilis and we therefore rename the gene aldB based on functional similarity to the Escherichia coli acetaldehyde dehydrogenase.

Identification of Low Population States in Cryo-EM Using Deep Learning

Cryo-EM has made extraordinary headway towards becoming a semi-automated, high-throughput structure determination technique. In the general workflow, high-to-medium population states are grouped into two- and three-dimensional classes, from which structures can be obtained with near-atomic resolution and subsequently analyzed to interpret function. However, low population states, which are also functionally important, are often discarded. Here, we describe a technique whereby low population states can be efficiently identified with minimal human effort via a deep convolutional neural network classifier. We use this deep learning classifier to describe a transient, low population state of bacteriophage A511 in the midst of infecting its bacterial host. This method can be used to further automate data collection and identify other functionally important low population states.