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Krishnan Vijayaraghavan D. Yamini V. Ambika N. Sravya Sowdamini 《Critical reviews in biotechnology》2013,33(1):67-77
This article highlights the research work carried out in the production of inulinases from various inulin substrates using strains of bacteria, yeast and fungi. Inulin is one of the numerous polysaccharides of plant origin that contains glucose or fructose. It is used as a substrate in industrial fermentation processes and in food industries due to its relatively cheap and abundant source for the microbiological production of high-fructose syrups, ethanol and acetone–butanol. The various oligosaccharides derived from inulin also find their application in the medical and dietary sector. The inulinase acts on the β-(2,1)-D-fructoside links in inulin releasing D-fructose. Hence, this article illustrates the capability of various microbes in hydrolyzing the carbon at its optimum nutrient concentration and operating condition towards inulinase production. 相似文献
44.
Christofer Bj?rkelid Terese Bergfors Anand Kumar V. Raichurkar Kakoli Mukherjee Krishnan Malolanarasimhan Balachandra Bandodkar T. Alwyn Jones 《The Journal of biological chemistry》2013,288(25):18260-18270
Mycobacterium tuberculosis, the bacterial causative agent of tuberculosis, currently affects millions of people. The emergence of drug-resistant strains makes development of new antibiotics targeting the bacterium a global health priority. Pantothenate kinase, a key enzyme in the universal biosynthesis of the essential cofactor CoA, was targeted in this study to find new tuberculosis drugs. The biochemical characterizations of two new classes of compounds that inhibit pantothenate kinase from M. tuberculosis are described, along with crystal structures of their enzyme-inhibitor complexes. These represent the first crystal structures of this enzyme with engineered inhibitors. Both classes of compounds bind in the active site of the enzyme, overlapping with the binding sites of the natural substrate and product, pantothenate and phosphopantothenate, respectively. One class of compounds also interferes with binding of the cofactor ATP. The complexes were crystallized in two crystal forms, one of which is in a new space group for this enzyme and diffracts to the highest resolution reported for any pantothenate kinase structure. These two crystal forms allowed, for the first time, modeling of the cofactor-binding loop in both open and closed conformations. The structures also show a binding mode of ATP different from that previously reported for the M. tuberculosis enzyme but similar to that in the pantothenate kinases of other organisms. 相似文献
45.
Chen Chen Vengadesan Krishnan Kevin Macon Kartik Manne Sthanam V. L. Narayana Olaf Schneewind 《The Journal of biological chemistry》2013,288(41):29440-29452
Staphylococcus epidermidis, a commensal of humans, secretes Esp protease to prevent Staphylococcus aureus biofilm formation and colonization. Blocking S. aureus colonization may reduce the incidence of invasive infectious diseases; however, the mechanism whereby Esp disrupts biofilms is unknown. We show here that Esp cleaves autolysin (Atl)-derived murein hydrolases and prevents staphylococcal release of DNA, which serves as extracellular matrix in biofilms. The three-dimensional structure of Esp was revealed by x-ray crystallography and shown to be highly similar to that of S. aureus V8 (SspA). Both atl and sspA are necessary for biofilm formation, and purified SspA cleaves Atl-derived murein hydrolases. Thus, S. aureus biofilms are formed via the controlled secretion and proteolysis of autolysin, and this developmental program appears to be perturbed by the Esp protease of S. epidermidis. 相似文献
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Covalent modification cycles are basic units and building blocks of posttranslational modification and cellular signal transduction. We systematically explore different spatial aspects of signal transduction in covalent modification cycles by starting with a basic temporal cycle as a reference and focusing on steady-state signal transduction. We consider, in turn, the effect of diffusion on spatial signal transduction, spatial analogs of ultrasensitive behavior, and the interplay between enzyme localization and substrate diffusion. Our analysis reveals the need to explicitly account for kinetics and diffusional transport (and localization) of enzymes, substrates, and complexes. It demonstrates a complex and subtle interplay between spatial heterogeneity, diffusion, and localization. Overall, examining the spatial dimension of covalent modification reveals that 1), there are important differences between spatial and temporal signal transduction even in this cycle; and 2), spatial aspects may play a substantial role in affecting and distorting information transfer in modules/networks that are usually studied in purely temporal terms. This has important implications for the systematic understanding of signaling in covalent modification cycles, pathways, and networks in multiple cellular contexts. 相似文献
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Naveen Admala Reddy Gopinath Adusumilli Raghu Devanna Rohra G Mayur Saravanan Pichai Sharmila Arujnan 《Indian journal of human genetics》2013,19(4):459-464
INTRODUCTION:
Non-syndromic tooth agenesis is a congenital anomaly with significant medical, psychological, and social ramifications. There is sufficient evidence to hypothesize that locus for this condition can be identified by candidate genes.AIM OF THE STUDY:
The aim of this study was to test whether MSX1 671 T > C gene variant was involved in etiology of non-syndromic tooth agenesis in Raichur patients.MATERIALS AND METHODS:
Blood samples were collected with informed consent from 50 subjects having non-syndromic tooth agenesis and 50 controls. Genomic deoxyribonucleic acid (DNA) was extracted from the blood samples, polymerase chain reaction (PCR) was performed, and restriction fragment length polymorphism (RFLP) was performed for digestion products that were evaluated.RESULTS:
The results showed positive correlation between MSX1671 T > C gene variant and non-syndromic tooth agenesis in Raichur patients.CONCLUSION:
MSX1 671 T > C gene variant may be a good screening marker for non-syndromic tooth agenesis in Raichur patients. 相似文献50.
Neetha John Moka Rajasekhar Katta Mohan Girisha Podila Satya Venkata Narasimha Sharma Puthiya Mundyat Gopinath 《Indian journal of human genetics》2013,19(2):165-170