Publications by authors named "Oliver Chammas"
The influence of heparin and heparan sulphate (HepS) on the appearance and analysis of open promoter complex (RP) formation by E. coli RNA polymerase (RNAP) holoenzyme (σRNAP) on linear DNA using ex situ imaging by atomic force microscopy (AFM) has been investigated. Introducing heparin or HepS into the reaction mix significantly reduces non-specific interactions of the σRNAP and RNAP after RP formation allowing for better interpretation of complexes shown within AFM images, particularly on DNA templates containing more than one promoter.
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- The study focuses on how dislocation-mediated stress relaxation in crystal growth differs when growing calcite (CaCO3) on organic self-assembled monolayers, as opposed to inorganic heterostructures.
- It uses Bragg coherent diffraction imaging to visualize the crystal structure and internal strain of calcite, revealing a consistent presence of a single dislocation loop in each crystal.
- The findings suggest that these dislocation loops have unique geometries influenced by interfacial defects and substrate roughness, highlighting significant differences in crystal growth behavior on organic versus inorganic substrates.
A polymerase chain reaction (PCR) based method of adding a single-stranded DNA (ssDNA) hairpin loop to one end of linear double-stranded (ds) DNA templates was developed. The loop structure serves as a fiducial marker in single molecule imaging by atomic force microscopy (AFM) and can be applied to study DNA-protein interactions. The nucleic acid end-labels allow discrimination of the polarity of the DNA template in the AFM while limiting non-specific interactions which might occur from non-nucleic acid labels.
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