Structural Basis for the Inhibition of Protein Biosynthesis: Mode of Action of Tubulosine

Science ◽  
1967 ◽  
Vol 157 (3784) ◽  
pp. 84-85 ◽  
Author(s):  
A. P. Grollman
Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 861
Author(s):  
Francis Opoku ◽  
Penny P. Govender ◽  
Ofentse J. Pooe ◽  
Mthokozisi B.C. Simelane

To date, Plasmodium falciparum is one of the most lethal strains of the malaria parasite. P. falciparum lacks the required enzymes to create its own purines via the de novo pathway, thereby making Plasmodium falciparum hypoxanthine-guanine-xanthine phosphoribosyltransferase (PfHGXPT) a crucial enzyme in the malaria life cycle. Recently, studies have described iso-mukaadial acetate and ursolic acid acetate as promising antimalarials. However, the mode of action is still unknown, thus, the current study sought to investigate the selective inhibitory and binding actions of iso-mukaadial acetate and ursolic acid acetate against recombinant PfHGXPT using in-silico and experimental approaches. Recombinant PfHGXPT protein was expressed using E. coli BL21 cells and homogeneously purified by affinity chromatography. Experimentally, iso-mukaadial acetate and ursolic acid acetate, respectively, demonstrated direct inhibitory activity towards PfHGXPT in a dose-dependent manner. The binding affinity of iso-mukaadial acetate and ursolic acid acetate on the PfHGXPT dissociation constant (KD), where it was found that 0.0833 µM and 2.8396 µM, respectively, are indicative of strong binding. The mode of action for the observed antimalarial activity was further established by a molecular docking study. The molecular docking and dynamics simulations show specific interactions and high affinity within the binding pocket of Plasmodium falciparum and human hypoxanthine-guanine phosphoribosyl transferases. The predicted in silico absorption, distribution, metabolism and excretion/toxicity (ADME/T) properties predicted that the iso-mukaadial acetate ligand may follow the criteria for orally active drugs. The theoretical calculation derived from ADME, molecular docking and dynamics provide in-depth information into the structural basis, specific bonding and non-bonding interactions governing the inhibition of malarial. Taken together, these findings provide a basis for the recommendation of iso-mukaadial acetate and ursolic acid acetate as high-affinity ligands and drug candidates against PfHGXPT.


2016 ◽  
Vol 2 (3) ◽  
pp. e1501502 ◽  
Author(s):  
Thiemo Sprink ◽  
David J. F. Ramrath ◽  
Hiroshi Yamamoto ◽  
Kaori Yamamoto ◽  
Justus Loerke ◽  
...  

Throughout the four phases of protein biosynthesis—initiation, elongation, termination, and recycling—the ribosome is controlled and regulated by at least one specified translational guanosine triphosphatase (trGTPase). Although the structural basis for trGTPase interaction with the ribosome has been solved for the last three steps of translation, the high-resolution structure for the key initiation trGTPase, initiation factor 2 (IF2), complexed with the ribosome, remains elusive. We determine the structure of IF2 complexed with a nonhydrolyzable guanosine triphosphate analog and initiator fMet-tRNAiMet in the context of the Escherichia coli ribosome to 3.7-Å resolution using cryo-electron microscopy. The structural analysis reveals previously unseen intrinsic conformational modes of the 70S initiation complex, establishing the mutual interplay of IF2 and initator transfer RNA (tRNA) with the ribsosome and providing the structural foundation for a mechanistic understanding of the final steps of translation initiation.


RNA ◽  
2008 ◽  
Vol 14 (8) ◽  
pp. 1590-1599 ◽  
Author(s):  
M. A. Borovinskaya ◽  
S. Shoji ◽  
K. Fredrick ◽  
J. H.D. Cate

2021 ◽  
Author(s):  
Grishma Vadlamani ◽  
Kirill V Sukhoverkov ◽  
Joel Haywood ◽  
Karen J Breese ◽  
Mark F Fisher ◽  
...  

Herbicides are vital for modern agriculture, but their utility is threatened by genetic or metabolic resistance in weeds as well as heightened regulatory scrutiny. Of the known herbicide modes of action, 6-hydroxymethyl-7,8-dihydropterin synthase (DHPS) which is involved in folate biosynthesis, is targeted by just one commercial herbicide, asulam. A mimic of the substrate para-aminobenzoic acid, asulam is chemically similar to sulfonamide antibiotics - and while still in widespread use, asulam has faced regulatory scrutiny. With an entire mode of action represented by just one commercial agrochemical, we sought to improve the understanding of its plant target. Here we solve a 2.6 Å resolution crystal structure for Arabidopsis thaliana DHPS that is conjoined to 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) and reveal a strong structural conservation with bacterial counterparts at the sulfonamide-binding pocket of DHPS. We demonstrate asulam and the antibiotics sulfacetamide and sulfamethoxazole have herbicidal as well as antibacterial activity and explore the structural basis of their potency by modelling these compounds in mitochondrial HPPK/DHPS. Our findings suggest limited opportunity for the rational design of plant selectivity from asulam and that pharmacokinetic or delivery differences between plants and microbes might be the best approaches to safeguard this mode of action.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 843
Author(s):  
Yen-Ting Lai

Viral entry into host cells is a critical step in the viral life cycle. HIV-1 entry is mediated by the sole surface envelope glycoprotein Env and is initiated by the interaction between Env and the host receptor CD4. This interaction, referred to as the attachment step, has long been considered an attractive target for inhibitor discovery and development. Fostemsavir, recently approved by the FDA, represents the first-in-class drug in the attachment inhibitor class. This review focuses on the discovery of temsavir (the active compound of fostemsavir) and analogs, mechanistic studies that elucidated the mode of action, and structural studies that revealed atomic details of the interaction between HIV-1 Env and attachment inhibitors. Challenges associated with emerging resistance mutations to the attachment inhibitors and the development of next-generation attachment inhibitors are also highlighted.


2007 ◽  
Vol 370 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Katsuro Yaoi ◽  
Hidemasa Kondo ◽  
Ayako Hiyoshi ◽  
Natsuko Noro ◽  
Hiroshi Sugimoto ◽  
...  

2021 ◽  
Author(s):  
Walther Mothes ◽  
Wenwei Li ◽  
Yaozong Chen ◽  
Jeremie Prevost ◽  
Irfan Ullah ◽  
...  

Emerging variants of concern for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can transmit more efficiently and partially evade protective immune responses, thus necessitating continued refinement of antibody therapies and immunogen design. Here we elucidate the structural basis and mode of action for two potent SARS-CoV-2 Spike (S) neutralizing monoclonal antibodies CV3-1 and CV3-25 that remained effective against emerging variants of concern in vitro and in vivo. CV3-1 bound to the (485-GFN-487) loop within the receptor-binding domain (RBD) in the RBD-up position and triggered potent shedding of the S1 subunit. In contrast, CV3-25 inhibited membrane fusion by binding to an epitope in the stem helix region of the S2 subunit that is highly conserved among beta-coronaviruses. Thus, vaccine immunogen designs that incorporate the conserved regions in RBD and stem helix region are candidates to elicit pan-coronavirus protective immune responses.


Author(s):  
IRA G. WOOL ◽  
WILLIAM S. STIREWALT ◽  
KENZO KURIHARA ◽  
ROBERT B. LOW ◽  
PHYLLIS BAILEY ◽  
...  

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