scispace - formally typeset
Search or ask a question
Author

Khajamohiddin Syed

Bio: Khajamohiddin Syed is an academic researcher from University of Zululand. The author has contributed to research in topics: Phanerochaete & Genome. The author has an hindex of 20, co-authored 47 publications receiving 3159 citations. Previous affiliations of Khajamohiddin Syed include University of Cincinnati Academic Health Center & University of Cincinnati.
Topics: Phanerochaete, Genome, Pyrene, Medicine, Biology


Papers
More filters
Journal ArticleDOI
29 Jun 2012-Science
TL;DR: Comparative analyses of 31 fungal genomes suggest that lignin-degrading peroxidases expanded in the lineage leading to the ancestor of the Agaricomycetes, which is reconstructed as a white rot species, and then contracted in parallel lineages leading to brown rot and mycorrhizal species.
Abstract: Wood is a major pool of organic carbon that is highly resistant to decay, owing largely to the presence of lignin. The only organisms capable of substantial lignin decay are white rot fungi in the Agaricomycetes, which also contains non-lignin-degrading brown rot and ectomycorrhizal species. Comparative analyses of 31 fungal genomes (12 generated for this study) suggest that lignin-degrading peroxidases expanded in the lineage leading to the ancestor of the Agaricomycetes, which is reconstructed as a white rot species, and then contracted in parallel lineages leading to brown rot and mycorrhizal species. Molecular clock analyses suggest that the origin of lignin degradation might have coincided with the sharp decrease in the rate of organic carbon burial around the end of the Carboniferous period.

1,396 citations

Journal ArticleDOI
TL;DR: Docking against homology-modeled targets also becomes possible for proteins whose structures are not known, and the druggability of the compounds and their specificity against a particular target can be calculated for further lead optimization processes.
Abstract: Molecular docking methodology explores the behavior of small molecules in the binding site of a target protein. As more protein structures are determined experimentally using X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy, molecular docking is increasingly used as a tool in drug discovery. Docking against homology-modeled targets also becomes possible for proteins whose structures are not known. With the docking strategies, the druggability of the compounds and their specificity against a particular target can be calculated for further lead optimization processes. Molecular docking programs perform a search algorithm in which the conformation of the ligand is evaluated recursively until the convergence to the minimum energy is reached. Finally, an affinity scoring function, ΔG [U total in kcal/mol], is employed to rank the candidate poses as the sum of the electrostatic and van der Waals energies. The driving forces for these specific interactions in biological systems aim toward complementarities between the shape and electrostatics of the binding site surfaces and the ligand or substrate.

817 citations

Journal ArticleDOI
TL;DR: In this paper, a comparative genome analysis of C. subvermispora and P. chrysosporium was conducted to investigate the basis for selective ligninolysis.
Abstract: Efficient lignin depolymerization is unique to the wood decay basidiomycetes, collectively referred to as white rot fungi. Phanerochaete chrysosporium simultaneously degrades lignin and cellulose, whereas the closely related species, Ceriporiopsis subvermispora, also depolymerizes lignin but may do so with relatively little cellulose degradation. To investigate the basis for selective ligninolysis, we conducted comparative genome analysis of C. subvermispora and P. chrysosporium. Genes encoding manganese peroxidase numbered 13 and five in C. subvermispora and P. chrysosporium, respectively. In addition, the C. subvermispora genome contains at least seven genes predicted to encode laccases, whereas the P. chrysosporium genome contains none. We also observed expansion of the number of C. subvermispora desaturase-encoding genes putatively involved in lipid metabolism. Microarray-based transcriptome analysis showed substantial up-regulation of several desaturase and MnP genes in wood-containing medium. MS identified MnP proteins in C. subvermispora culture filtrates, but none in P. chrysosporium cultures. These results support the importance of MnP and a lignin degradation mechanism whereby cleavage of the dominant nonphenolic structures is mediated by lipid peroxidation products. Two C. subvermispora genes were predicted to encode peroxidases structurally similar to P. chrysosporium lignin peroxidase and, following heterologous expression in Escherichia coli, the enzymes were shown to oxidize high redox potential substrates, but not Mn2+. Apart from oxidative lignin degradation, we also examined cellulolytic and hemicellulolytic systems in both fungi. In summary, the C. subvermispora genetic inventory and expression patterns exhibit increased oxidoreductase potential and diminished cellulolytic capability relative to P. chrysosporium.

263 citations

Journal ArticleDOI
Luis M. Corrochano1, Alan Kuo2, Marina Marcet-Houben3, Silvia Polaino4, Asaf Salamov2, José Manuel Villalobos-Escobedo, Jane Grimwood2, M. Isabel Isabel Álvarez5, Javier Avalos1, Diane Bauer2, Ernesto P. Benito5, Isabelle Benoit6, Gertraud Burger7, Lola P. Camino1, David Cánovas1, Enrique Cerdá-Olmedo1, Jan Fang Cheng2, Angel Domínguez5, Marek Eliáš8, Arturo P. Eslava5, Fabian Glaser9, Gabriel Gutiérrez1, Joseph Heitman10, Bernard Henrissat11, Bernard Henrissat12, Enrique A. Iturriaga5, B. Franz Franz Lang7, José Luis Lavín, Soo Chan Lee10, Wenjun Li10, Erika Lindquist2, Sergio López-García13, Eva M. Luque1, Ana T. Marcos1, Joel Martin2, Kevin McCluskey14, Humberto R. Medina1, Alejandro Miralles-Durán1, Atsushi Miyazaki15, Elisa Muñoz-Torres5, José A. Oguiza16, Robin A. Ohm2, María Teresa Camacho Olmedo1, Margarita Orejas17, Lucila Ortiz-Castellanos18, Antonio G. Pisabarro16, Julio Rodríguez-Romero1, José Ruiz-Herrera18, Rosa M. Ruiz-Vázquez13, Catalina Sanz5, Wendy Schackwitz2, Mahdi Shahriari5, Ekaterina Shelest19, Fatima Silva-Franco13, Darren M. Soanes20, Khajamohiddin Syed21, Víctor G. Tagua1, Nicholas J. Talbot20, Michael R. Thon5, Hope Tice2, Ronald P. de Vries6, Ad Wiebenga6, Jagjit S. Yadav21, Edward L. Braun22, Scott E. Baker23, Victoriano Garre13, Jeremy Schmutz2, Benjamin A. Horwitz9, Santiago Torres-Martínez13, Alexander Idnurm4, Alexander Idnurm24, Alfredo Herrera-Estrella, Toni Gabaldón25, Toni Gabaldón3, Igor V. Grigoriev2 
TL;DR: The genome duplication provided the means to improve signal transduction for enhanced perception of environmental signals and will help to understand the role of genome dynamics in the evolution of sensory perception in eukaryotes.

148 citations

Journal ArticleDOI
TL;DR: The P. carnosa genome is enriched with genes that encode P450 monooxygenases that can participate in extractives degradation, and manganese peroxidases involved in lignin degradation, which could be correlated to the utilization of heartwood and sapwood preparations from both coniferous and hardwood species.
Abstract: Softwood is the predominant form of land plant biomass in the Northern hemisphere, and is among the most recalcitrant biomass resources to bioprocess technologies. The white rot fungus, Phanerochaete carnosa, has been isolated almost exclusively from softwoods, while most other known white-rot species, including Phanerochaete chrysosporium, were mainly isolated from hardwoods. Accordingly, it is anticipated that P. carnosa encodes a distinct set of enzymes and proteins that promote softwood decomposition. To elucidate the genetic basis of softwood bioconversion by a white-rot fungus, the present study reports the P. carnosa genome sequence and its comparative analysis with the previously reported P. chrysosporium genome. P. carnosa encodes a complete set of lignocellulose-active enzymes. Comparative genomic analysis revealed that P. carnosa is enriched with genes encoding manganese peroxidase, and that the most divergent glycoside hydrolase families were predicted to encode hemicellulases and glycoprotein degrading enzymes. Most remarkably, P. carnosa possesses one of the largest P450 contingents (266 P450s) among the sequenced and annotated wood-rotting basidiomycetes, nearly double that of P. chrysosporium. Along with metabolic pathway modeling, comparative growth studies on model compounds and chemical analyses of decomposed wood components showed greater tolerance of P. carnosa to various substrates including coniferous heartwood. The P. carnosa genome is enriched with genes that encode P450 monooxygenases that can participate in extractives degradation, and manganese peroxidases involved in lignin degradation. The significant expansion of P450s in P. carnosa, along with differences in carbohydrate- and lignin-degrading enzymes, could be correlated to the utilization of heartwood and sapwood preparations from both coniferous and hardwood species.

130 citations


Cited by
More filters
28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

01 Aug 2000
TL;DR: Assessment of medical technology in the context of commercialization with Bioentrepreneur course, which addresses many issues unique to biomedical products.
Abstract: BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

4,833 citations

01 May 2005

2,648 citations

Journal Article
TL;DR: FastTree as mentioned in this paper uses sequence profiles of internal nodes in the tree to implement neighbor-joining and uses heuristics to quickly identify candidate joins, then uses nearest-neighbor interchanges to reduce the length of the tree.
Abstract: Gene families are growing rapidly, but standard methods for inferring phylogenies do not scale to alignments with over 10,000 sequences. We present FastTree, a method for constructing large phylogenies and for estimating their reliability. Instead of storing a distance matrix, FastTree stores sequence profiles of internal nodes in the tree. FastTree uses these profiles to implement neighbor-joining and uses heuristics to quickly identify candidate joins. FastTree then uses nearest-neighbor interchanges to reduce the length of the tree. For an alignment with N sequences, L sites, and a different characters, a distance matrix requires O(N^2) space and O(N^2 L) time, but FastTree requires just O( NLa + N sqrt(N) ) memory and O( N sqrt(N) log(N) L a ) time. To estimate the tree's reliability, FastTree uses local bootstrapping, which gives another 100-fold speedup over a distance matrix. For example, FastTree computed a tree and support values for 158,022 distinct 16S ribosomal RNAs in 17 hours and 2.4 gigabytes of memory. Just computing pairwise Jukes-Cantor distances and storing them, without inferring a tree or bootstrapping, would require 17 hours and 50 gigabytes of memory. In simulations, FastTree was slightly more accurate than neighbor joining, BIONJ, or FastME; on genuine alignments, FastTree's topologies had higher likelihoods. FastTree is available at http://microbesonline.org/fasttree.

2,436 citations

Journal ArticleDOI
TL;DR: Approaches used for drug repurposing (also known as drug repositioning) are presented, the challenges faced by the repurpose community are discussed, and innovative ways by which these challenges could be addressed are recommended to help realize the full potential of drugRepurposing.
Abstract: Given the high attrition rates, substantial costs and slow pace of new drug discovery and development, repurposing of 'old' drugs to treat both common and rare diseases is increasingly becoming an attractive proposition because it involves the use of de-risked compounds, with potentially lower overall development costs and shorter development timelines. Various data-driven and experimental approaches have been suggested for the identification of repurposable drug candidates; however, there are also major technological and regulatory challenges that need to be addressed. In this Review, we present approaches used for drug repurposing (also known as drug repositioning), discuss the challenges faced by the repurposing community and recommend innovative ways by which these challenges could be addressed to help realize the full potential of drug repurposing.

2,365 citations