DNA glycosylases protect genomic integrity by locating and excising aberrant nucleobases. Substrate recognition and excision usually take place in an extrahelical conformation, which is often stabilized by π-stacking interactions between the lesion nucleobase and aromatic side chains in the glycosylase active site. Bacillus cereus AlkD is the only DNA glycosylase known to catalyze base excision without extruding the damaged nucleotide from the DNA helix. Instead of contacting the nucleobase itself, the AlkD active site interacts with the lesion deoxyribose through a series of C-H/π interactions. These interactions are ubiquitous in protein structures, but evidence for their catalytic significance in enzymology is lacking. Here, we show that the C-H/π interactions between AlkD and the lesion deoxyribose participate in catalysis of glycosidic bond cleavage. This is the first demonstration of a catalytic role for C-H/π interactions as intermolecular forces important to DNA repair.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5034759 | PMC |
http://dx.doi.org/10.1021/jacs.6b07399 | DOI Listing |
J Phys Chem B
December 2024
Crystallography & Molecular Biology Division, Saha Institute of Nuclear Physics, Kolkata 700064, India.
The artificial metalloenzyme containing iridium in place of iron along with four directed evolution mutations C317G, T213G, L69V, and V254L in a natural cytochrome P450 presents an important milestone in merging the extraordinary efficiency of biocatalysts with the versatility of small molecule chemical catalysts in catalyzing a new-to-nature carbene insertion reaction. This is a show-stopper enzyme, as it exhibits a catalytic efficiency similar to that of natural enzymes. Despite this remarkable discovery, there is no mechanistic and structural understanding as to why it displays extraordinary efficiency after the incorporation of the four active site mutations by directed evolution methods, which so far has been intractable to any experimental methods.
View Article and Find Full Text PDFAnal Chem
December 2024
Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education; Key Laboratory of Eco-environmental Polymer Materials of Gansu Province; College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China.
Improving the selective and sensitive binding properties of macrocyclic hosts to target guests is always an interesting challenge. Herein, we introduce a novel "bis-clamp-cavity synergy" strategy to enhance the selectivity and binding sensitivity of pillararenes toward target guests. To achieve this goal, we designed and synthesized ,'-bis-hydroxynaphthoylhydrazone-functionalized conjugated pillar[5]arene (), in which bis-hydroxynaphthoylhydrazone plays the role of clamps, while the pillar[5]arene provides the macrocyclic cavity.
View Article and Find Full Text PDFActa Crystallogr C Struct Chem
November 2024
Instituto de Física de São Carlos, Universidade de São Paulo, USP, Avenida Trabalhador São-Carlense, No. 400 Parque Arnold Schmidt - CEP 13566-590, São Carlos, SP, Brazil.
J Phys Chem A
November 2024
Department of Chemistry, Nanoscale Sciences and Technology Institute, Nanocarbon R&D Institute, Wonkwang University, Iksan, Jeonbuk 54538, R.O.K.
We studied the hydroboration of the C fullerene using both B3LYP-D3(BJ)/6-311G(d,p) and M06-2X-D3/6-311G(d,p) levels of theory, incorporating the empirical dispersion interaction, and Fukui index calculations. Potential energy surfaces (PESs) and Gibbs free energy surfaces (GFESs) were calculated for the pathways from four BH adducts (located at the , , , and sites) on the C to eight products formed by the 1,2-addition of BH across the four [6,6]-ring fused bonds (, , , and ) and across the two [5,6]-ring fused bonds ( and ). These pathways are two-step consecutive reactions.
View Article and Find Full Text PDFNat Commun
August 2024
Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!