Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Shiva K. Angala is active.

Publication


Featured researches published by Shiva K. Angala.


Molecular Microbiology | 2009

Menaquinone synthesis is critical for maintaining mycobacterial viability during exponential growth and recovery from non-replicating persistence.

Rakesh K. Dhiman; Sebabrata Mahapatra; Richard A. Slayden; Melissa E. Boyne; Anne J. Lenaerts; Jerald C. Hinshaw; Shiva K. Angala; Delphi Chatterjee; Kallolmay Biswas; Prabagaran Narayanasamy; Michio Kurosu; Dean C. Crick

Understanding the basis of bacterial persistence in latent infections is critical for eradication of tuberculosis. Analysis of Mycobacterium tuberculosis mRNA expression in an in vitro model of non‐replicating persistence indicated that the bacilli require electron transport chain components and ATP synthesis for survival. Additionally, low μM concentrations of aminoalkoxydiphenylmethane derivatives inhibited both the aerobic growth and survival of non‐replicating, persistent M. tuberculosis. Metabolic labelling studies and quantification of cellular menaquinone levels suggested that menaquinone synthesis, and consequently electron transport, is the target of the aminoalkoxydiphenylmethane derivatives. This hypothesis is strongly supported by the observations that treatment with these compounds inhibits oxygen consumption and that supplementation of growth medium with exogenous menaquinone rescued both growth and oxygen consumption of treated bacilli. In vitro assays indicate that the aminoalkoxydiphenylmethane derivatives specifically inhibit MenA, an enzyme involved in the synthesis of menaquinone. Thus, the results provide insight into the physiology of mycobacterial persistence and a basis for the development of novel drugs that enhance eradication of persistent bacilli and latent tuberculosis.


Critical Reviews in Biochemistry and Molecular Biology | 2014

The cell envelope glycoconjugates of Mycobacterium tuberculosis

Shiva K. Angala; Juan Manuel Belardinelli; Emilie Huc-Claustre; William H. Wheat; Mary Jackson

Abstract Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of the most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last 10 years in the discovery and development of novel inhibitors targeting their biogenesis.


BMC Microbiology | 2012

Production of mycobacterial cell wall glycopeptidolipids requires a member of the MbtH-like protein family

Elizabeth Tatham; Sivagami Sundaram Chavadi; Poornima Mohandas; Uthamaphani R. Edupuganti; Shiva K. Angala; Delphi Chatterjee; Luis E. N. Quadri

BackgroundGlycopeptidolipids (GPLs) are among the major free glycolipid components of the outer membrane of several saprophytic and clinically-relevant Mycobacterium species. The architecture of GPLs is based on a constant tripeptide-amino alcohol core of nonribosomal peptide synthetase origin that is N-acylated with a 3-hydroxy/methoxy acyl chain synthesized by a polyketide synthase and further decorated with variable glycosylation patterns built from methylated and acetylated sugars. GPLs have been implicated in many aspects of mycobacterial biology, thus highlighting the significance of gaining an understanding of their biosynthesis. Our bioinformatics analysis revealed that every GPL biosynthetic gene cluster known to date contains a gene (referred herein to as gplH) encoding a member of the MbtH-like protein family. Herein, we sought to conclusively establish whether gplH was required for GPL production.ResultsDeletion of gplH, a gene clustered with nonribosomal peptide synthetase-encoding genes in the GPL biosynthetic gene cluster of Mycobacterium smegmatis, produced a GPL deficient mutant. Transformation of this mutant with a plasmid expressing gplH restored GPL production. Complementation was also achieved by plasmid-based constitutive expression of mbtH, a paralog of gplH found in the biosynthetic gene cluster for production of the siderophore mycobactin of M. smegmatis. Further characterization of the gplH mutant indicated that it also displayed atypical colony morphology, lack of sliding motility, altered capacity for biofilm formation, and increased drug susceptibility.ConclusionsHerein, we provide evidence formally establishing that gplH is essential for GPL production in M. smegmatis. Inactivation of gplH also leads to a pleiotropic phenotype likely to arise from alterations in the cell envelope due to the lack of GPLs. While genes encoding MbtH-like proteins have been shown to be needed for production of siderophores and antibiotics, our study presents the first case of one such gene proven to be required for production of a cell wall component. Furthermore, our results provide the first example of a mbtH-like gene with confirmed functional role in a member of the Mycobacterium genus. Altogether, our findings demonstrate a critical role of gplH in mycobacterial biology and advance our understanding of the genetic requirements for the biosynthesis of an important group of constituents of the mycobacterial outer membrane.


ACS Infectious Diseases | 2016

Structure–Function Profile of MmpL3, the Essential Mycolic Acid Transporter from Mycobacterium tuberculosis

Juan M. Belardinelli; Amira Yazidi; Liang Yang; Lucien Fabre; Wei Li; Benoit Jacques; Shiva K. Angala; Isabelle Rouiller; Helen I. Zgurskaya; Jurgen Sygusch; Mary Jackson

The MmpL family of proteins translocates complex (glyco)lipids and siderophores across the cell envelope of mycobacteria and closely related Corynebacteriaceae and plays important roles in the biogenesis of the outer membrane of these organisms. Despite their significance in the physiology and virulence of Mycobacterium tuberculosis, and from the perspective of developing novel antituberculosis agents, little is known about their structure and mechanism of translocation. In this study, the essential mycobacterial mycolic acid transporter, MmpL3, and its orthologue in Corynebacterium glutamicum, CmpL1, were investigated as prototypical MmpL proteins to gain insight into the transmembrane topology, tertiary and quaternary structures, and functional regions of this transporter family. The combined genetic, biochemical, and biophysical studies indicate that MmpL3 and CmpL1 are structurally similar to Gram-negative resistance-nodulation and division efflux pumps. They harbor 12 transmembrane segments interrupted by two large soluble periplasmic domains and function as homotrimers to export long-chain (C22-C90) mycolic acids, possibly in their acetylated form, esterified to trehalose. The mapping of a number of functional residues within the middle region of the transmembrane domain of MmpL3 shows a striking overlap with mutations associated with resistance to MmpL3 inhibitors. The results suggest that structurally diverse inhibitors of MmpL3 all target the proton translocation path of the transporter and that multiresistance to these inhibitors is enabled by conformational changes in MmpL3.


Journal of Biological Chemistry | 2012

A Small Multidrug Resistance-like Transporter Involved in the Arabinosylation of Arabinogalactan and Lipoarabinomannan in Mycobacteria

Gérald Larrouy-Maumus; Henrieta Škovierová; Rabeb Dhouib; Shiva K. Angala; Sophie Zuberogoitia; Ha Pham; Anne Drumond Villela; Katarína Mikušová; Audrey Noguera; Martine Gilleron; Lucia Valentínová; Jana Korduláková; Patrick J. Brennan; Germain Puzo; Jérôme Nigou; Mary Jackson

Background: (Glyco)lipid translocation across the plasma membrane plays a pivotal role in the biogenesis of the mycobacterial cell envelope. Results: The SMR-likes transporter Rv3789 appears to be involved in reorienting decaprenol phosphate arabinose to the periplasm. Conclusion: Rv3789 participates in the buildup of the arabinan domains of arabinogalactan and lipoarabinomannan. Significance: This is the first lipid-linked sugar translocase ever identified in mycobacteria. The biosynthesis of the major cell envelope glycoconjugates of Mycobacterium tuberculosis is topologically split across the plasma membrane, yet nothing is known of the transporters required for the translocation of lipid-linked sugar donors and oligosaccharide intermediates from the cytoplasmic to the periplasmic side of the membrane in mycobacteria. One of the mechanisms used by prokaryotes to translocate lipid-linked phosphate sugars across the plasma membrane relies on translocases that share resemblance with small multidrug resistance transporters. The presence of an small multidrug resistance-like gene, Rv3789, located immediately upstream from dprE1/dprE2 responsible for the formation of decaprenyl-monophosphoryl-β-d-arabinose (DPA) in the genome of M. tuberculosis led us to investigate its potential involvement in the formation of the major arabinosylated glycopolymers, lipoarabinomannan (LAM) and arabinogalactan (AG). Disruption of the ortholog of Rv3789 in Mycobacterium smegmatis resulted in a reduction of the arabinose content of both AG and LAM that accompanied the accumulation of DPA in the mutant cells. Interestingly, AG and LAM synthesis was restored in the mutant not only upon expression of Rv3789 but also upon that of the undecaprenyl phosphate aminoarabinose flippase arnE/F genes from Escherichia coli. A bacterial two-hybrid system further indicated that Rv3789 interacts in vivo with the galactosyltransferase that initiates the elongation of the galactan domain of AG. Biochemical and genetic evidence is thus consistent with Rv3789 belonging to an AG biosynthetic complex, where its role is to reorient DPA to the periplasm, allowing this arabinose donor to then be used in the buildup of the arabinan domains of AG and LAM.


ACS Chemical Biology | 2011

Reconstitution of functional mycobacterial arabinosyltransferase AftC proteoliposome and assessment of decaprenylphosphorylarabinose analogues as arabinofuranosyl donors.

Jian Zhang; Shiva K. Angala; Pradeep K. Pramanik; Kai Li; Dean C. Crick; Abraham Liav; Adam Jozwiak; Ewa Swiezewska; Mary Jackson; Delphi Chatterjee

Arabinosyltransferases are a family of membrane-bound glycosyltransferases involved in the biosynthesis of the arabinan segment of two key glycoconjugates, arabinogalactan and lipoarabinomannan, in the mycobacterial cell wall. All arabinosyltransferases identified have been found to be essential for the growth of Mycobcterium tuberculosis and are potential targets for developing new antituberculosis drugs. Technical bottlenecks in designing enzyme assays for screening for inhibitors of these enzymes are (1) the enzymes are membrane proteins and refractory to isolation; and (2) the sole arabinose donor, decaprenylphosphoryl-d-arabinofuranose is sparingly produced and difficult to isolate, and commercial substrates are not available. In this study, we have synthesized several analogues of decaprenylphosphoryl-d-arabinofuranose by varying the chain length and investigated their arabinofuranose (Araf) donating capacity. In parallel, an essential arabinosyltransferase (AftC), an enzyme that introduces α-(1→3) branch points in the internal arabinan domain in both arabinogalactan and lipoarabinomannan synthesis, has been expressed, solubilized, and purified for the first time. More importantly, it has been shown that the AftC is active only when reconstituted in a proteoliposome using mycobacterial phospholipids and has a preference for diacylated phosphatidylinositoldimannoside (Ac(2)PIM(2)), a major cell wall associated glycolipid. α-(1→3) branched arabinans were generated when AftC-liposome complex was used in assays with the (Z,Z)-farnesylphosphoryl d-arabinose and linear α-d-Araf-(1→5)(3-5) oligosaccharide acceptors and not with the acceptor that had a α-(1→3) branch point preintroduced.


Nature Communications | 2016

Structural basis for selective recognition of acyl chains by the membrane-associated acyltransferase PatA

David Albesa-Jové; Zuzana Svetlíková; Montse Tersa; Enea Sancho-Vaello; Ana Carreras-González; Pascal Bonnet; Pedro Arrasate; Ander Eguskiza; Shiva K. Angala; Javier O. Cifuente; Jana Korduláková; Mary Jackson; Katarína Mikušová; Marcelo E. Guerin

The biosynthesis of phospholipids and glycolipids are critical pathways for virtually all cell membranes. PatA is an essential membrane associated acyltransferase involved in the biosynthesis of mycobacterial phosphatidyl-myo-inositol mannosides (PIMs). The enzyme transfers a palmitoyl moiety from palmitoyl–CoA to the 6-position of the mannose ring linked to 2-position of inositol in PIM1/PIM2. We report here the crystal structures of PatA from Mycobacterium smegmatis in the presence of its naturally occurring acyl donor palmitate and a nonhydrolyzable palmitoyl–CoA analog. The structures reveal an α/β architecture, with the acyl chain deeply buried into a hydrophobic pocket that runs perpendicular to a long groove where the active site is located. Enzyme catalysis is mediated by an unprecedented charge relay system, which markedly diverges from the canonical HX4D motif. Our studies establish the mechanistic basis of substrate/membrane recognition and catalysis for an important family of acyltransferases, providing exciting possibilities for inhibitor design.


Journal of Biological Chemistry | 2016

Assembling of the Mycobacterium tuberculosis Cell Wall Core

Anna E. Grzegorzewicz; Célia de Sousa-d'Auria; Michael R. McNeil; Emilie Huc-Claustre; Victoria Jones; Cécile Petit; Shiva K. Angala; Júlia Zemanová; Qinglan Wang; Juan Manuel Belardinelli; Qian Gao; Yoshimasa Ishizaki; Katarína Mikušová; Patrick J. Brennan; Donald R. Ronning; Mohamed Chami; Christine Houssin; Mary Jackson

The unique cell wall of mycobacteria is essential to their viability and the target of many clinically used anti-tuberculosis drugs and inhibitors under development. Despite intensive efforts to identify the ligase(s) responsible for the covalent attachment of the two major heteropolysaccharides of the mycobacterial cell wall, arabinogalactan (AG) and peptidoglycan (PG), the enzyme or enzymes responsible have remained elusive. We here report on the identification of the two enzymes of Mycobacterium tuberculosis, CpsA1 (Rv3267) and CpsA2 (Rv3484), responsible for this function. CpsA1 and CpsA2 belong to the widespread LytR-Cps2A-Psr (LCP) family of enzymes that has been shown to catalyze a variety of glycopolymer transfer reactions in Gram-positive bacteria, including the attachment of wall teichoic acids to PG. Although individual cpsA1 and cpsA2 knock-outs of M. tuberculosis were readily obtained, the combined inactivation of both genes appears to be lethal. In the closely related microorganism Corynebacterium glutamicum, the ortholog of cpsA1 is the only gene involved in this function, and its conditional knockdown leads to dramatic changes in the cell wall composition and morphology of the bacteria due to extensive shedding of cell wall material in the culture medium as a result of defective attachment of AG to PG. This work marks an important step in our understanding of the biogenesis of the unique cell envelope of mycobacteria and opens new opportunities for drug development.


Journal of Biological Chemistry | 2014

A single arabinan chain is attached to the phosphatidylinositol mannosyl core of the major immunomodulatory mycobacterial cell envelope glycoconjugate, lipoarabinomannan.

Devinder Kaur; Shiva K. Angala; Sz-Wei Wu; Kay-Hooi Khoo; Delphi Chatterjee; Patrick J. Brennan; Mary Jackson; Michael R. McNeil

Background: Important details of the structures of lipomannan and lipoarabinomannan remain unknown. Results: New details on the branching structure of LM and the number of arabinan chains in LAM are here provided. Conclusion: Mature LAM carries a single arabinan chain attached near the middle of the mannan core. Significance: Results allow for a working model of the biosynthetic pathway of LM and LAM. Lipoarabinomannan (LAM) is composed of a phosphatidylinositol anchor followed by a mannan followed by an arabinan that may be capped with various motifs including oligosaccharides of mannose. A related polymer, lipomannan (LM), is composed of only the phosphatidylinositol and mannan core. Both the structure and the biosynthesis of LAM have been studied extensively. However, fundamental questions about the branching structure of LM and the number of arabinan chains on the mannan backbone in LAM remain. LM and LAM molecules produced by three different glycosyltransferase mutants of Mycobacterium smegmatis were used here to investigate these questions. Using an MSMEG_4241 mutant that lacks the α-(1,6)-mannosyltransferase used late in LM elongation, we showed that the reducing end region of the mannan that is attached to inositol has 5–7 unbranched α-6-linked-mannosyl residues followed by two or three α-6-linked mannosyl residues branched with single α-mannopyranose residues at O-2. After these branched mannosyl residues, the α-6-linked mannan chain is terminated with an α-mannopyranose at O-2 rather than O-6 of the penultimate residue. Analysis of the number of arabinans attached to the mannan core of LM in two other mutants (ΔembC and ΔMSMEG_4247) demonstrated exactly one arabinosyl substitution of the mannan core suggestive of the arabinosylation of a linear LM precursor with ∼10–12 mannosyl residues followed by additional mannosylation of the core and arabinosylation of a single arabinosyl “primer.” Thus, these studies suggest that only a single arabinan chain attached near the middle of the mannan core is present in mature LAM and allow for an updated working model of the biosynthetic pathway of LAM and LM.


PLOS Neglected Tropical Diseases | 2013

Regulation of Mycolactone, the Mycobacterium ulcerans Toxin, Depends on Nutrient Source

Caroline Deshayes; Shiva K. Angala; Estelle Marion; Irène Brandli; Jérémie Babonneau; Laurent Preisser; Sara Eyangoh; Yves Delneste; Pierre Legras; Chantal de Chastellier; Timothy P. Stinear; Mary Jackson; Laurent Marsollier

Background Mycobacterium ulcerans, a slow-growing environmental bacterium, is the etiologic agent of Buruli ulcer, a necrotic skin disease. Skin lesions are caused by mycolactone, the main virulence factor of M. ulcerans, with dermonecrotic (destruction of the skin and soft tissues) and immunosuppressive activities. This toxin is secreted in vesicles that enhance its biological activities. Nowadays, it is well established that the main reservoir of the bacilli is localized in the aquatic environment where the bacillus may be able to colonize different niches. Here we report that plant polysaccharides stimulate M. ulcerans growth and are implicated in toxin synthesis regulation. Methodology/Principal Findings In this study, by selecting various algal components, we have identified plant-specific carbohydrates, particularly glucose polymers, capable of stimulating M. ulcerans growth in vitro. Furthermore, we underscored for the first time culture conditions under which the polyketide toxin mycolactone, the sole virulence factor of M. ulcerans identified to date, is down-regulated. Using a quantitative proteomic approach and analyzing transcript levels by RT-qPCR, we demonstrated that its regulation is not at the transcriptional or translational levels but must involve another type of regulation. M. ulcerans produces membrane vesicles, as other mycobacterial species, in which are the mycolactone is concentrated. By transmission electron microscopy, we observed that the production of vesicles is independent from the toxin production. Concomitant with this observed decrease in mycolactone production, the production of mycobacterial siderophores known as mycobactins was enhanced. Conclusions/Significance This work is the first step in the identification of the mechanisms involved in mycolactone regulation and paves the way for the discovery of putative new drug targets in the future.

Collaboration


Dive into the Shiva K. Angala's collaboration.

Top Co-Authors

Avatar

Mary Jackson

University of Massachusetts Medical School

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Patrick J. Brennan

Brigham and Women's Hospital

View shared research outputs
Top Co-Authors

Avatar

Dean C. Crick

Colorado State University

View shared research outputs
Top Co-Authors

Avatar

Avraham Liav

Colorado State University

View shared research outputs
Top Co-Authors

Avatar

Jérôme Nigou

Paul Sabatier University

View shared research outputs
Top Co-Authors

Avatar

Katarína Mikušová

Comenius University in Bratislava

View shared research outputs
Top Co-Authors

Avatar

Anita G. Amin

Colorado State University

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge