Salmonella typhimurium Mutants Defective in Cytidine Monophosphate Kinase (cmk)

Salmonella typhimurium mutants defective in cytidine monophosphate kinase (cmk).

Mutants of Salmonella typhimurium defective in cytidine 5'-monophosphate (CMP) kinase (cmk) have been isolated. The mutants also lack the ability to phosphorylate 2'-deoxyCMP, indicating that one enzyme is responsible for the phosphorylation of both CMP and deoxyCMP to the corresponding diphosphates. In glucose minimal medium the mutants grow at the same rate as the parental strain; however, th...

Mutants of Salmonella typhimurium requiring cytidine for growth.

One would expect that the mutational loss of cytidine triphosphate synthetase (Fig. 1) reaction (9) would result in a strain which requires cytosine or cytidine for growth; however, to our knowledge, no such mutants have been isolated (B. Magasanik, p. 295-334, In I. C. Gunsalus and R. Y. Stanier [ed.], The Bacteria, vol. 3. Academic Press, Inc., New York, 1962). Failure to isolate mutants with...

Salmonella typhimurium prfA mutants defective in release factor 1.

Mutations have been characterized that map in the prfA gene of Salmonella typhimurium. These weak amber suppressors show increased readthrough of UAG but not UAA or UGA codons. Some hemA mutants exhibit a similar suppressor activity due to transcriptional polarity on prfA. All of the suppressors mapping in prfA are recessive to the wild type. Two mutant prfA genes were cloned onto plasmids, and...

Characterization of thiL, encoding thiamin-monophosphate kinase, in Salmonella typhimurium.

Thiamin pyrophosphate is an essential cofactor that is synthesized de novo by Salmonella typhimurium. In bacteria, the end product of the de novo biosynthetic pathway is thiamin monophosphate, which is then phosphorylated by thiamin-monophosphate kinase (EC 2.7.4.16) to form thiamin pyrophosphate. We have isolated and characterized the thiL gene of S. typhimurium and showed that thiL is a 978-b...

Salmonella typhimurium proline mutants.