| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

and
Jorge C. Escalante-Semerena*
Department of Bacteriology, University of Wisconsin—Madison, 144A Enzyme Institute, 1710 University Avenue, Madison, Wisconsin 53726-4087
Received 25 May 2007/ Accepted 4 August 2007
Cobinamide (Cbi) salvaging is impaired, but not abolished, in a Salmonella enterica strain lacking a functional cobU gene. CobU is a bifunctional enzyme (NTP:adenosylcobinamide [NTP:AdoCbi] kinase, GTP:adenosylcobinamide-phosphate [GTP:AdoCbi-P] guanylyltransferase) whose AdoCbi kinase activity is necessary for Cbi salvaging in this bacterium. Inactivation of the ycfN gene in a
cobU strain abrogated Cbi salvaging. Introduction of a plasmid carrying the ycfN+ allele into a
cobU
ycfN strain substantially restored Cbi salvaging. Mass spectrometry data indicate that when YcfN-enriched cell extracts were incubated with AdoCbi and ATP, the product of the reaction was AdoCbi-P. Results from bioassays confirmed that YcfN converted AdoCbi to AdoCbi-P in an ATP-dependent manner. YcfN is a good example of enzymes that are used by the cell in multiple pathways to ensure the salvaging of valuable precursors.
Published ahead of print on 10 August 2007.
Present address: The Salk Institute Plant Biology Laboratory, La Jolla, CA 92037.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |