INTRODUCTION One of our projects involved the development of a transformation and transposon mutagenesis systems for the bacterium that causes Pierce's disease (PD), Xylella fastidiosa (Xf). We now have a random transposon mutagenesis system working for Xf (Guilhabert, et al. 2001) and recently we have developed an E. coli/Xf plasmid shuttle vector. We are currently assessing the stability of t...

Directed evolution is a common technique to engineer enzymes for a diverse set of applications. Structural information and an understanding of how proteins respond to mutation and recombination are being used to develop improved directed evolution strategies by increasing the probability that mutant sequences have the desired properties. Strategies that target mutagenesis to particular regions ...

The DEK oncoprotein regulates cellular chromatin function via a number of protein–protein interactions. However, the biological relevance its unique pseudo-SAP/SAP-box domain, which transmits DNA modulating activities in vitro, remains largely speculative. As hypothesis-driven mutations failed to yield DNA-binding null (DBN) mutants, we combined random mutagenesis with Bacterial Growth Inhibiti...

The mouse continues to play a vital role in the deciphering of mammalian gene function and the modelling of human neurological disease. Advances in gene targeting technologies have facilitated the efficiency of generating new mouse mutants, although this valuable resource has rapidly expanded in recent years due to a number of major random mutagenesis programmes. The phenotype-driven mutagenesi...

The reactivation of triosephosphate isomerase (TIM) from unfolded monomers induced by guanidine hydrochloride involves different amino acids of its sequence in different stages of protein refolding. We describe a systematic mutagenesis method to find critical residues for certain physico-chemical properties of a protein. The two similar TIMs of Trypanosoma brucei and Trypanosoma cruzi have diff...

Mutagenesis of protein-encoding sequences occurs ubiquitously; it enables evolution, accumulates during aging, and is associated with disease. Many biotechnological methods exploit random mutations to evolve novel proteins. To quantitate protein tolerance to random change, it is vital to understand the probability that a random amino acid replacement will lead to a protein's functional inactiva...

Computer simulations of the evolution of linear sequences have demonstrated the importance of recombination of blocks of sequence rather than point mutagenesis alone. Repeated cycles of point mutagenesis, recombination, and selection should allow in vitro molecular evolution of complex sequences, such as proteins. A method for the reassembly of genes from their random DNA fragments, resulting i...

Although the composition of the gut microbiota and its symbiotic contribution to key host physiological functions are well established, little is known as yet about the bacterial factors that account for this symbiosis. We selected Lactobacillus casei as a model microorganism to proceed to genomewide identification of the functions required for a symbiont to establish colonization in the gut. A...

background: finding shows that there were several problems in the treatment of helicobacter pylori infection such as the emergence of resistance to the antibiotics, the risk of recrudescence, and the high cost of treatment. the ineffectiveness of conventional treatment mechanisms against cancer cells reveals the importance of peptides as a novel therapeutic approach. however, the short length o...