The “zipper” is a well known design pattern for providing a cursorlike interface to a data structure. However, the classic treatise by Huet only scratches the surface of some of the potential applications of the zipper. In this paper we take inspiration from Huet, and build a library suitable as an underpinning for a structured editor for programming languages. We consider a zipper structure th...

We show that four of the five Platonic solids’ surfaces may be cut open with a Hamiltonian path along edges and unfolded to a polygonal net each of which can “zipper-refold” to a flat doubly covered parallelogram, forming a rather compact representation of the surface. Thus these regular polyhedra have particular flat “zipper pairs.” No such zipper pair exists for a dodecahedron, whose Hamilton...

We introduce the Random Access Zipper (RAZ), a simple, purely-functional data structure for editable sequences. The RAZ combines the structure of a zipper with that of a tree: like a zipper, edits at the cursor require constant time; by leveraging tree structure, relocating the edit cursor in the sequence requires log time. While existing data structures provide these time bounds, none do so wi...

Fibrous proteins in the amyloid state are found both associated with numerous diseases and in the normal functions of cells. Amyloid fibers contain a repetitive spine, commonly built from a pair of β-sheets whose β-strands run perpendicular to the fiber direction and whose side chains interdigitate, much like the teeth of a zipper. In fiber spines known as homosteric zippers, identical protein ...

Drosophila is an ideal metazoan model system for analyzing the role of nonmuscle myosin-II (henceforth, myosin) during development. In Drosophila, myosin function is required for cytokinesis and morphogenesis driven by cell migration and/or cell shape changes during oogenesis, embryogenesis, larval development and pupal metamorphosis. The mechanisms that regulate myosin function and the supramo...

We cloned cDNA encoding chicken cytoplasmic histone acetyltransferase-1, chHAT-1, comprising 408 amino acids including a putative initiation Met. It exhibits 80.4% identity to the human homolog and possesses a typical leucine zipper motif. The glutathione S:-transferase (GST) pull-down assay, involving truncated and missense mutants of the chicken chromatin assembly factor-1 (chCAF-1)p48, revea...

We introduce another item in the already large list of techniques for attribute evaluation. Our algorithm consists in computing an attributes by reduction to normal form using a transducer operating on tree encodings of a cyclic representation of zippers. A zipper is a data structure introduced by Gérard Huet for representing a subtree together with its context, i.e. it is a tree with a focus t...

We have developed a bZIP protein, GBF-F, with both dominant-negative (DN) and gain-of-function properties. GBF-F is a chimera consisting of two components: the DNA binding (basic) region from the plant bZIP protein GBF-1 (GBF) and a leucine zipper (F) designed to preferentially heterodimerize with the C/EBP alpha leucine zipper. Biochemical studies show that GBF-F preferentially forms heterodim...

Formation of R-helical coiled-coil dimers represents one of the simplest examples of a specific protein-protein interaction. This dimerization mode is commonly observed among transcription regulator proteins, where the process is referred to as leucine zipper formation. Inhibitors of leucine zipper dimerization would allow one to control gene expression. As a first step toward identifying such ...

Polyamines and polyamine analogues have been demonstrated to modulate the transcription of various genes. Spermidine/spermine N(1)-acetyltransferase (SSAT) is transcriptionally regulated through the interaction of at least two trans-acting transcription factors, NF-E2-related factor 2 (Nrf-2) and PMF-1 (polyamine modulated factor-1). Nrf-2 has previously been shown to regulate transcription of ...