Plasmid F'(128) was formed by an exchange between chromosomal Rep sequences that placed lac near dinB between many pairs of Rep sequences. Plasmid F'(128) is critical for selection-enhanced lac reversion (adaptive mutation), which requires prior lac amplification. The structure of F'(128) supports the idea that amplification is initiated by Rep-Rep recombination and that general mutagenesis req...

E. coli Rep protein is a 3' to 5' SF1 superfamily DNA helicase which is monomeric in the absence of DNA, but can dimerize upon binding either single-stranded or duplex DNA. A variety of biochemical studies have led to proposals that Rep dimerization is important for its helicase activity; however, recent structural studies of Bacillus stearothermophilus PcrA have led to suggestions that SF1 hel...

The origin of replication of African cassava mosaic virus (ACMV) and a gene expression vector based on Potato virus X were exploited to devise an in planta system for functional analysis of the geminivirus replication-associated protein (Rep) in transgenic Nicotiana benthamiana line pOri-2. This line contains an integrated copy of a tandem repeat of the ACMV origin of replication flanking nonvi...

A rep-tiling ~is a self replicating, lattice tiling of R". Lattice tiling means a tiling by translates of a single compact tile by the points of a lattice, and self-replicating means that there is a non-singular linear map ¢: R"-o R" such that, for each T e J, the image 4~(T) is, in turn, tiled by Y-. This topic has recently come under investigation, not only because of its recreational appeal,...

DNA helicases are motor proteins that unwind duplex DNA during DNA replication, recombination and repair in reactions that are coupled to ATP binding and hydrolysis. In the process of unwinding duplex DNA processively, DNA helicases must also translocate along the DNA filament. To probe the mechanism of ATP-driven translocation by the dimeric E. coli Rep helicase along single stranded (ss) DNA,...

A family of repetitive extragenic palindromic (REP) sequences is composed of hundreds of copies distributed throughout the chromosome. Their palindromic nature and conservation suggested that they are specifically recognized by a protein(s). We have identified DNA gyrase [DNA topoisomerase (ATP-hydrolysing), EC 5.99.1.3] as one of the REP-binding proteins. Gyrase has at least a 10-fold higher a...

The replication initiator protein (Rep) of plasmid ColE2-P9 (ColE2) is multifunctional. We are interested in how Rep binds to the origin (Ori) to perform various functions. We used the wild type and variants of Rep to study the Rep-Ori interaction by both in vitro and in vivo approaches, including biochemical analyses of protein-DNA interactions and an in vivo replication assay. We identified t...

Adeno-associated virus (AAV) is a single-stranded parvovirus retaining the unique capacity for site-specific integration into a transcriptionally silent region of the human genome, a characteristic requiring the functional properties of the Rep 78/68 polypeptide in conjunction with AAV terminal repeat integrating elements. Previous strategies designed to assemble these genetic elements into ade...

The probability of "replication," P(rep), has been proposed as a means of identifying replicable and reliable effects in the psychological sciences. We conduct a basic test of P(rep) that reveals that it misestimates the true probability of replication, especially for small effects. We show how these general problems with P(rep) play out in practice, when it is applied to predict the replicabil...

Hepatic ischemia/reperfusion (ISCH/REP) is a major clinical problem that is considered to be the most common cause of postoperative liver failure. Recently, mast cells have been proposed to play an important role in the pathophysiology of ISCH/REP in many organs. In contrast, the role played by mast cells during ISCH/REP-induced liver damage has remained an issue of debate. This study aimed to ...