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WE CONTINUE with Professor Jacob D Bekenstein, the star of the past series of posts, with a paper that audaciously suggests that the evidence points to a universe as a giant hologram. This is a beautifully articulated article written for the non-specialist — but, dear reader — after surviving the past two dizzyingly technical papers as primers, this should be a breeze! https://www.scientificamerican.com/article/information-in-the-holographic-univ/ View in LinkedIn

CAUSE OF ZIG-ZAG. The unusual backbone is associated with guanosine residues which have an unusual conformation. NMR studies in solution have shown that purine residues can adopt the syn and anti conformations with equal ease. Another difference is found in the pucker of the sugar ring.” https://link.springer.com/content/pdf/10.1007/978-94-009-7052-6.pdf View in LinkedIn

ZIG-ZAG ALTERNATION. “The left-handed helix has the phosphates arranged in a zig-zag array; hence the name Z-DNA. The same Z structure has been found in crystals of tetramers d(CpGpCpG) as well as in other hexamer crystals.” https://link.springer.com/content/pdf/10.1007/978-94-009-7052-6.pdf View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend and concludes this weekend on a paper from the early days of untangling the structure of DNA, by Professor Alexander Rich from MIT, featuring the unraveling of left handed DNA. The story is written in crystal clear language, with unyielding logic, an historical milestone. https://link.springer.com/content/pdf/10.1007/978-94-009-7052-6.pdf View in LinkedIn

HISTORICAL MARKER IN THE SAND. “After the discovery of Z-DNA, oplnlons were mixed as to its relevance to biology. It was clear that Z-DNA could form only under specialized conditions that would stabilize it.” https://link.springer.com/content/pdf/10.1007/978-94-009-7052-6.pdf View in LinkedIn

METHYLATION VARIANTS. “The structural studies thus account for the considerable change in the equilibrium between B-DNA and Z-DNA. It also provides a structural rationale for why methylation of DNA might favor the formation of small segments of Z-DNA.” https://link.springer.com/content/pdf/10.1007/978-94-009-7052-6.pdf View in LinkedIn

STABILIZATION OF CONFORMER. “The stabilization of Z-DNA by methylation is due to two factors.” https://link.springer.com/content/pdf/10.1007/978-94-009-7052-6.pdf View in LinkedIn

STRUCTURAL CONSEQUENCES. “One of the features apparent in the structural work was the fact that OG sequences play an important role in the Z conformation.” https://link.springer.com/content/pdf/10.1007/978-94-009-7052-6.pdf View in LinkedIn