Disease relevance of dnaK

• Only one dnaK homolog, dnaK2, is active transcriptionally and is essential in Synechocystis [1].
• Construction of a new reporter system to study the NaCl-dependent dnaK promoter activity of Lactobacillus sanfranciscensis [2].
• We have isolated lambda dnaJ+ transducing phages both by in vitro cloning and by abnormal excision of a lambda dnaK transducing phage integrated near the dnaJ locus [3].
• Plasmid replication and Hfr formation in strains of Escherichia coli carrying seg mutations [4].

High impact information on dnaK

• This increase was present in groE and dnaK mutants but was inhibited in cells treated with chloramphenicol and novobiocin [5].
• The active dnaK (seg) gene product is therefore essential for replication of the mini-F plasmid at both 30 degrees and 42 degrees C [6].
• The seg mutants (seg-1 and seg-2) of Escherichia coli cannot support the replication of the F factor and mini-F plasmids at 42 degrees C. We cloned the wild-type E. coli chromosomal DNA fragment complementing the seg-1 and seg-2 mutations and found that both mutations were complemented by the wild-type dnaK gene coding for a heat shock protein [6].
• Cloning and sequencing of the dnaK gene of the seg mutants showed that there was one base substitution within the dnaK gene in each mutant causing an amino acid substitution [6].
• The resulting recombinant plasmids contained the genes uvrA, groP (B534 or B612), and lexA [7].

Chemical compound and disease context of dnaK

• The gro mutation, groPC259, is recessive to wild type and maps between threonine (thr) and diaminopimelate (dapB) on the E. coli chromosome [8].

Biological context of dnaK

• The reporter system was validated by demonstrating the induction of the dnaK operon of L. sanfranciscensis by NaCl stress [2].
• The gene affected is designated seg and has been located by transduction in the serB-thr segment of the chromosome [9].
• Several conditional-lethal mutantions that do not permit the replication of F-factors of Escherichia coli K-12 are located at a site called seg [4].
• A new host gene (groPC) necessary for lambda DNA replication [8].

Other interactions of dnaK

• F-genote formation from seg Hfr stains is dependent on a functional recA gene, as F-genote formation was not seen with a seg-2, recA-1 Hfr [4].

Analytical, diagnostic and therapeutic context of dnaK

• After removal of the gro signal sequence by site-directed mutagenesis, the vector was introduced to E. coli JM109 [10].

References