ORCID Profile
0000-0003-0771-253X
Current Organisations
National Institutes of Health
,
NCBI/NLM/NIH
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Publisher: American Association for the Advancement of Science (AAAS)
Date: 24-03-2017
Abstract: NAD + can influence DNA repair by modulating protein interactions.
Publisher: Proceedings of the National Academy of Sciences
Date: 19-03-2018
Abstract: Mutagenic AID/APOBEC deaminases (AADs) are central to processes such as generation of antibody ersity and antiviral defense in vertebrates. Their presence and role outside vertebrates are poorly characterized. We report the discovery of several AADs, including some that are secreted, across erse metazoan, dictyosteliid, and algal lineages. They appear to have emerged from an early transfer of an AAD from bacterial toxin systems, followed by extensive ersification into multiple eukaryotic clades, showing dramatic structural innovation, rapid ergence, gene loss, polymorphism, and lineage-specific expansions. We uncover evidence for their ergence in arms-race scenarios with viruses and genomic retroelements and show that AAD-based nucleic acid mutagenesis as a basis of immune defense is widespread across metazoa, slime molds, and algae.
Publisher: Oxford University Press (OUP)
Date: 07-09-2020
DOI: 10.1093/NAR/GKAA726
Abstract: ABC ATPases form one of the largest clades of P-loop NTPase fold enzymes that catalyze ATP-hydrolysis and utilize its free energy for a staggering range of functions from transport to nucleoprotein dynamics. Using sensitive sequence and structure analysis with comparative genomics, for the first time we provide a comprehensive classification of the ABC ATPase superfamily. ABC ATPases developed structural hallmarks that unambiguously distinguish them from other P-loop NTPases such as an alternative to arginine-finger-based catalysis. At least five and up to eight distinct clades of ABC ATPases are reconstructed as being present in the last universal common ancestor. They underwent distinct phases of structural innovation with the emergence of inserts constituting conserved binding interfaces for proteins or nucleic acids and the adoption of a unique dimeric toroidal configuration for DNA-threading. Specifically, several clades have also extensively radiated in counter-invader conflict systems where they serve as nodal nucleotide-dependent sensory and energetic components regulating a ersity of effectors (including some previously unrecognized) acting independently or together with restriction-modification systems. We present a unified mechanism for ABC ATPase function across disparate systems like RNA editing, translation, metabolism, DNA repair, and biological conflicts, and some unexpected recruitments, such as MutS ATPases in secondary metabolism.
Publisher: MDPI AG
Date: 05-01-2021
DOI: 10.3390/V13010063
Abstract: Jumbo phages have attracted much attention by virtue of their extraordinary genome size and unusual aspects of biology. By performing a comparative genomics analysis of 224 jumbo phages, we suggest an objective inclusion criterion based on genome size distributions and present a synthetic overview of their manifold adaptations across major biological systems. By means of clustering and principal component analysis of the phyletic patterns of conserved genes, all known jumbo phages can be classified into three higher-order groups, which include both myoviral and siphoviral morphologies indicating multiple independent origins from smaller predecessors. Our study uncovers several under-appreciated or unreported aspects of the DNA replication, recombination, transcription and virion maturation systems. Leveraging sensitive sequence analysis methods, we identify novel protein-modifying enzymes that might help hijack the host-machinery. Focusing on host–virus conflicts, we detect strategies used to counter different wings of the bacterial immune system, such as cyclic nucleotide- and NAD+-dependent effector-activation, and prevention of superinfection during pseudolysogeny. We reconstruct the RNA-repair systems of jumbo phages that counter the consequences of RNA-targeting host effectors. These findings also suggest that several jumbo phage proteins provide a snapshot of the systems found in ancient replicons preceding the last universal ancestor of cellular life.
Publisher: Springer Science and Business Media LLC
Date: 15-02-2001
DOI: 10.1038/35057062
Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.
Publisher: Springer Science and Business Media LLC
Date: 13-07-2009
DOI: 10.1038/NI.1769
No related grants have been discovered for L Aravind.