The thermodynamic profiles of target site recognition have been surveyed for homing endonucleases from various structural families. Similar to DNA-binding proteins that recognize shorter target sites, homing endonucleases display a narrow range of binding free energies and affinities, mediated by structural interactions that balance the magnitude of enthalpic and entropic forces. While the balance of DeltaH and TDeltaS are not strongly correlated with the overall extent of DNA bending, unfavorable DeltaH(binding) is associated with unstacking of individual base steps in the target site. The effects of deleterious basepair substitutions in the optimal target sites of two LAGLIDADG homing endonucleases, and the subsequent effect of redesigning one of those endonucleases to accommodate that DNA sequence change, were also measured. The substitution of base-specific hydrogen bonds in a wild-type endonuclease/DNA complex with hydrophobic van der Waals contacts in a redesigned complex reduced the ability to discriminate between sites, due to nonspecific DeltaS(binding).
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http://dx.doi.org/10.1093/nar/gkm867 | DOI Listing |
Genome Res
October 2024
Innovative Genomics Institute, University of California, Berkeley, California 94720, USA;
BMC Microbiol
September 2024
Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.
Background: Bacillus cereus is a Gram-positive, spore-forming bacterium that produces a spectrum of effectors integral to bacterial niche adaptation and the development of various infections. Among those is EsxA, whose secretion depends on the EssC component of the type VII secretion system (T7SS). EsxA's roles within the bacterial cell are poorly understood, although postulations indicate that it may be involved in sporulation.
View Article and Find Full Text PDFMitochondrial DNA B Resour
September 2024
Hans Merensky Chair in Avocado Research, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
The mitochondrial genome of is 121,350 base pairs in length with a G + C content of 30.19%. Phylogenetic analysis showed that grouped with other members of the Xylariaceae, with which its mitogenome also shares a broadly similar architecture and gene content.
View Article and Find Full Text PDFInt J Mol Sci
August 2024
State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650032, China.
Limited exploration in fungal mitochondrial genetics has uncovered diverse inheritance modes. The mitochondrial genomes are inherited uniparentally in the majority of sexual eukaryotes, our discovery of persistent mitochondrial heterogeneity within the natural population of the basidiomycete fungus represents a significant advance in understanding mitochondrial inheritance and evolution in eukaryotes. Here, we present a comprehensive analysis by sequencing and assembling the complete mitogenomes of 40 samples exhibiting diverse heterogeneity patterns from various geographical origins.
View Article and Find Full Text PDFElife
August 2024
Department of Biosciences, Rice University, Houston, United States.
Metal-ion-dependent nucleases play crucial roles in cellular defense and biotechnological applications. Time-resolved crystallography has resolved catalytic details of metal-ion-dependent DNA hydrolysis and synthesis, uncovering the essential roles of multiple metal ions during catalysis. The histidine-metal (His-Me) superfamily nucleases are renowned for binding one divalent metal ion and requiring a conserved histidine to promote catalysis.
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