scholarly journals Evolution of Parallel Spindles Like genes in plants and highlight of unique domain architecture#

2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Riccardo Aiese Cigliano ◽  
Walter Sanseverino ◽  
Gaetana Cremona ◽  
Federica M Consiglio ◽  
Clara Conicella
Keyword(s):  
Domain Architecture ◽  
Parallel Spindles ◽  
Unique Domain

scholarly journals Human Miro Proteins Act as NTP Hydrolases through a Novel, Non-Canonical Catalytic Mechanism

2018 ◽  
Vol 19 (12) ◽  
pp. 3839 ◽  
Author(s):  
Daniel Peters ◽  
Laura Kay ◽  
Jeyanthy Eswaran ◽  
Jeremy Lakey ◽  
Meera Soundararajan
Keyword(s):  
Catalytic Mechanism ◽  
Catalytic Domain ◽  
Domain Architecture ◽  
Subcellular Localisation ◽  
Cellular Processes ◽  
Calcium Sensing ◽  
And Function ◽  
Arginine Finger ◽  
Catalytic Functions ◽  
Unique Domain

Mitochondria are highly dynamic organelles that play a central role in multiple cellular processes, including energy metabolism, calcium homeostasis and apoptosis. Miro proteins (Miros) are “atypical” Ras superfamily GTPases that display unique domain architecture and subcellular localisation regulating mitochondrial transport, autophagy and calcium sensing. Here, we present systematic catalytic domain characterisation and structural analyses of human Miros. Despite lacking key conserved catalytic residues (equivalent to Ras Y32, T35, G60 and Q61), the Miro N-terminal GTPase domains display GTPase activity. Surprisingly, the C-terminal GTPase domains previously assumed to be “relic” domains were also active. Moreover, Miros show substrate promiscuity and function as NTPases. Molecular docking and structural analyses of Miros revealed unusual features in the Switch I and II regions, facilitating promiscuous substrate binding and suggesting the usage of a novel hydrolytic mechanism. The key substitution in position 13 in the Miros leads us to suggest the existence of an “internal arginine finger”, allowing an unusual catalytic mechanism that does not require GAP protein. Together, the data presented here indicate novel catalytic functions of human Miro atypical GTPases through altered catalytic mechanisms.

scholarly journals A Novel Peroxiredoxin Activity Is Located within the C-Terminal End of Rhodospirillum rubrum Adenylyltransferase

2007 ◽  
Vol 190 (1) ◽  
pp. 434-437 ◽  
Author(s):  
Anders Jonsson ◽  
Pedro Filipe Teixeira ◽  
Stefan Nordlund
Keyword(s):  
Glutamine Synthetase ◽  
Rhodospirillum Rubrum ◽  
Domain Architecture ◽  
Carboxyl Terminal ◽  
Unique Domain ◽  
First Time

ABSTRACT Adenylyltransferase (GlnE) catalyzes the reversible adenylylation of glutamine synthetase. In this report we present, for the first time, evidence for a peroxiredoxin activity of Rhodospirillum rubrum GlnE, through the carboxyl-terminal AhpC/thiol-specific antioxidant (TSA) domain. The combination of GlnE and AhpC/TSA domains within the same polypeptide constitutes a unique domain architecture that has not previously been identified among proteobacteria.

scholarly journals Structure and two-metal mechanism of a eukaryal nick-sealing RNA ligase

2015 ◽  
Vol 112 (45) ◽  
pp. 13868-13873 ◽  
Author(s):  
Mihaela-Carmen Unciuleac ◽  
Yehuda Goldgur ◽  
Stewart Shuman
Keyword(s):  
Reaction Pathway ◽  
Domain Architecture ◽  
Coordination Complex ◽  
Metal Coordination ◽  
Rna Repair ◽  
Rna Ligase ◽  
Dna Ligases ◽  
Catalytic Metal ◽  
Rna Capping ◽  
Unique Domain

ATP-dependent RNA ligases are agents of RNA repair that join 3′-OH and 5′-PO4 RNA ends. Naegleria gruberi RNA ligase (NgrRnl) exemplifies a family of RNA nick-sealing enzymes found in bacteria, viruses, and eukarya. Crystal structures of NgrRnl at three discrete steps along the reaction pathway—covalent ligase-(lysyl-Nζ)–AMP•Mn2+ intermediate; ligase•ATP•(Mn2+)2 Michaelis complex; and ligase•Mn2+ complex—highlight a two-metal mechanism of nucleotidyl transfer, whereby (i) an enzyme-bound “catalytic” metal coordination complex lowers the pKa of the lysine nucleophile and stabilizes the transition state of the ATP α phosphate; and (ii) a second metal coordination complex bridges the β- and γ-phosphates. The NgrRnl N domain is a distinctively embellished oligonucleotide-binding (OB) fold that engages the γ-phosphate and associated metal complex and orients the pyrophosphate leaving group for in-line catalysis with stereochemical inversion at the AMP phosphate. The unique domain architecture of NgrRnl fortifies the theme that RNA ligases have evolved many times, and independently, by fusions of a shared nucleotidyltransferase domain to structurally diverse flanking modules. The mechanistic insights to lysine adenylylation gained from the NgrRnl structures are likely to apply broadly to the covalent nucleotidyltransferase superfamily of RNA ligases, DNA ligases, and RNA capping enzymes.

Plant carotenoid cleavage oxygenases: structure–function relationships and role in development and metabolism

2019 ◽  
Vol 19 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Manoj Kumar Dhar ◽  
Sonal Mishra ◽  
Archana Bhat ◽  
Sudha Chib ◽  
Sanjana Kaul
Keyword(s):  
Higher Plants ◽  
Domain Architecture ◽  
Heme Iron ◽  
Critical Assessment ◽  
Protein Family ◽  
Regulatory Mechanisms ◽  
Non Heme Iron ◽  
Functional Aspects ◽  
Functional Understanding ◽  
Signal Production

Abstract A plant communicates within itself and with the outside world by deploying an array of agents that include several attractants by virtue of their color and smell. In this category, the contribution of ‘carotenoids and apocarotenoids’ is very significant. Apocarotenoids, the carotenoid-derived compounds, show wide representation among organisms. Their biosynthesis occurs by oxidative cleavage of carotenoids, a high-value reaction, mediated by carotenoid cleavage oxygenases or carotenoid cleavage dioxygenases (CCDs)—a family of non-heme iron enzymes. Structurally, this protein family displays wide diversity but is limited in its distribution among plants. Functionally, this protein family has been recognized to offer a role in phytohormones, volatiles and signal production. Further, their wide presence and clade-specific functional disparity demands a comprehensive account. This review focuses on the critical assessment of CCDs of higher plants, describing recent progress in their functional aspects and regulatory mechanisms, domain architecture, classification and localization. The work also highlights the relevant discussion for further exploration of this multi-prospective protein family for the betterment of its functional understanding and improvement of crops.

scholarly journals Connectivity characterization of the mouse basolateral amygdalar complex

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Houri Hintiryan ◽  
Ian Bowman ◽  
David L. Johnson ◽  
Laura Korobkova ◽  
Muye Zhu ◽  
...  
Keyword(s):  
Granular Cell ◽  
Cell Types ◽  
Projection Neurons ◽  
Cell Type ◽  
Connectivity Map ◽  
Analysis Techniques ◽  
Domain Specific ◽  
Cell Type Specific ◽  
Unique Domain

AbstractThe basolateral amygdalar complex (BLA) is implicated in behaviors ranging from fear acquisition to addiction. Optogenetic methods have enabled the association of circuit-specific functions to uniquely connected BLA cell types. Thus, a systematic and detailed connectivity profile of BLA projection neurons to inform granular, cell type-specific interrogations is warranted. Here, we apply machine-learning based computational and informatics analysis techniques to the results of circuit-tracing experiments to create a foundational, comprehensive BLA connectivity map. The analyses identify three distinct domains within the anterior BLA (BLAa) that house target-specific projection neurons with distinguishable morphological features. We identify brain-wide targets of projection neurons in the three BLAa domains, as well as in the posterior BLA, ventral BLA, posterior basomedial, and lateral amygdalar nuclei. Inputs to each nucleus also are identified via retrograde tracing. The data suggests that connectionally unique, domain-specific BLAa neurons are associated with distinct behavior networks.

scholarly journals Beyond Arabidopsis: BBX Regulators in Crop Plants

2021 ◽  
Vol 22 (6) ◽  
pp. 2906
Author(s):  
Urszula Talar ◽  
Agnieszka Kiełbowicz-Matuk
Keyword(s):  
Stress Tolerance ◽  
Crop Plants ◽  
Abiotic Stress Response ◽  
Biotic And Abiotic Stress ◽  
Photoperiodic Regulation ◽  
Large Families ◽  
Stress Related Genes ◽  
Unique Domain ◽  
Clock Mechanism

B-box proteins represent diverse zinc finger transcription factors and regulators forming large families in various plants. A unique domain structure defines them—besides the highly conserved B-box domains, some B-box (BBX) proteins also possess CCT domain and VP motif. Based on the presence of these specific domains, they are mostly classified into five structural groups. The particular members widely differ in structure and fulfill distinct functions in regulating plant growth and development, including seedling photomorphogenesis, the anthocyanins biosynthesis, photoperiodic regulation of flowering, and hormonal pathways. Several BBX proteins are additionally involved in biotic and abiotic stress response. Overexpression of some BBX genes stimulates various stress-related genes and enhanced tolerance to different stresses. Moreover, there is evidence of interplay between B-box and the circadian clock mechanism. This review highlights the role of BBX proteins as a part of a broad regulatory network in crop plants, considering their participation in development, physiology, defense, and environmental constraints. A description is also provided of how various BBX regulators involved in stress tolerance were applied in genetic engineering to obtain stress tolerance in transgenic crops.

Sign in / Sign up

Export Citation Format

Share Document