In previous work, at least 10 discrete cistrons involved in the synthesis of flagella in Escherichia coli were described. Six cistrons were located between his and uvrC on the genetic map. These were referred to as hag, flaA, flaB, flaC, flaD, and flaE. Four cistrons referred to as mot, flaG, flaH, and flaI were located between uvrC and aroD. In order to determine whether these genes are organi...

Nucleotide excision repair (NER) is universally used to recognize and remove many types of DNA damage. In eubacteria, the NER system typically consists of UvrA, UvrB, UvrC, the UvrD helicase, DNA polymerase I, and ligase. In addition, when DNA damage blocks transcription, transcription-repair coupling factor (TRCF), the product of the mfd gene, recruits the Uvr complex to repair the damage. Pre...

Exposure of Escherichia coli to the antibiotic mitomycin C (MTC) at a concentration of 0.5 mug/ml caused cross-linkage between complementary strands of deoxyribonucleic acid (DNA). Derivatives of mitomycin, 7-methoxymitosene (7-MMT) and decarbamoyl mitomycin C (DCMTC), at a level as high as 20 mug/ml formed no cross-links between DNA strands. Ultraviolet light-sensitive mutants of E. coli K-12 ...

Flagellar mutants in Escherichia coli were obtained by selection for resistance to the flagellotropic phage chi. F elements covering various regions of the E. coli genome were then constructed, and, on the basis of the ability of these elements to restore flagellar function, the mutations were assigned to three regions of the E. coli chromosome. Region I is between trp and gal; region II is bet...

The halophilic archaeon Halococcus hamelinensis was isolated from living stromatolites in Shark Bay, Western Australia, that are known to be exposed to extreme conditions of salinity, desiccation, and UV radiation. Modern stromatolites are considered analogues of very early life on Earth and thus inhabitants of modern stromatolites, and Hcc. hamelinensis in particular, are excellent candidates ...

Purified UvrA, UvrB, UvrC, UvrD, PolA and Lig proteins from Escherichia coli have been used to assess the effect of nucleotide excision repair on the conformation of native negatively supercoiled plasmid DNA in an in vitro test system. The analysis of labeled reaction products on specific gel systems suggests that the Uvr excinuclease has the ability to restrain the superhelical stress in the t...