We have subjected 12 different codons of a synthetic Lactobacillus casei thymidylate synthase (TS) gene to saturation site-directed mutagenesis to create amino acid "replacement sets" at each of those positions. The target residues were chosen because they are highly conserved and because they are important for the structure and function of the protein as indicated by solution and structural st...

background: among all common techniques in sitedirectedmutagenesis, λ red recombinase system has beenwidely used to knock out chromosomal genes in bacteria. in thismethod, there is always the risk of dna linear digestion byhost's restriction enzymes that leads to the low frequency ofrecombination. objectives:to overcome this, we constructeda recombinant vector to disrupt phop gene in salmonella...

Methods enabling mutational analysis of distinct chromosomal locations, like site-directed mutagenesis, insertion of foreign sequences or in-frame deletions, have become of fast growing interest since complete bacterial genome sequences became available. Various approaches have been described to modify any nucleotide(s) in almost any manner. Some genetic engineering technologies do not rely on ...

zymatic and biochemical propenies were examined. Three mutallts, P50S, DI08L, and DIZ3N, showed fairly low Hindlll activity. Oll the ether halld, the other £ouv, P84Q, E86K, VI06E, alld K125N, retained the activity. In particu1ar, E86K showed higher actiyity than the wild enzyme. This fact was confirmed when actiyities ef the purMed wild and E86K enzymes were assayed. These results coincided fa...

Site-directed mutagenesis (SDM) as a powerful technique was used to change two important and conserved amino acids in 5-enolpyruvylshikimate 3- phosphate synthase (EPSPS) gene of E. coli. The mutations changed glycine 96 to alanine and alanine 183 to threonine. These two amino acids are very important for intraction of the wide spectrum herbicide, glyphosate, to EPSP synthase enzymes. By design...

Human granulocyte colony stimulating factor (hG-CSF) induces proliferation and differentiation of granulocyte progenitor cells. This glycoprotein is currently being used for treatment of neutropenia, in patients who have undergone bone marrow transplantation. So far, different researchers have tried to enhance hG-CSF biological activity and stability. In this study, Polymerase Chain Reaction (P...