Abstract
Corrinoid (vitamin B12-like) cofactors contain various α-axial ligands, including 5,6-dimethylbenzimidazole (DMB) or adenine. The bacterium Salmonella enterica produces the corrin ring only under anaerobic conditions, but it can form "complete" corrinoids aerobically by importing an "incomplete" corrinoid, such as cobinamide (Cbi), and adding appropriate α- and β-axial ligands. Under aerobic conditions, S. enterica performs the corrinoid-dependent degradation of ethanolamine if given vitamin B12, but it can make B12 from exogenous Cbi only if DMB is also provided. Mutants isolated for their ability to degrade ethanolamine without added DMB converted Cbi to pseudo-B12 cofactors (having adenine as an α-axial ligand). The mutations cause an increase in the level of free adenine and install adenine (instead of DMB) as an α-ligand. When DMB is provided to these mutants, synthesis of pseudo-B12 cofactors ceases and B12 cofactors are produced, suggesting that DMB regulates production or incorporation of free adenine as an α-ligand. Wild-type cells make pseudo-B12 cofactors during aerobic growth on propanediol plus Cbi and can use pseudo-vitamin B12 for all of their corrinoid-dependent enzymes. Synthesis of coenzyme pseudo-B12 cofactors requires the same enzymes (CobT, CobU, CobS, and CobC) that install DMB in the formation of coenzyme B12. Models are described for the mechanism and control of α-axial ligand installation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1160-1171 |
| Number of pages | 12 |
| Journal | Journal of Bacteriology |
| Volume | 190 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 2008 |
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ASJC Scopus subject areas
- Applied Microbiology and Biotechnology
- Immunology
Cite this
One pathway can incorporate either adenine or dimethylbenzimidazole as an α-axial ligand of B12 cofactors in Salmonella enterica. / Anderson, Peter J.; Lango, Jozsef; Carkeet, Colleen; Britten, Audrey; Kräutler, Bernhard; Hammock, Bruce D.; Roth, John R.
In: Journal of Bacteriology, Vol. 190, No. 4, 02.2008, p. 1160-1171.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - One pathway can incorporate either adenine or dimethylbenzimidazole as an α-axial ligand of B12 cofactors in Salmonella enterica
AU - Anderson, Peter J.
AU - Lango, Jozsef
AU - Carkeet, Colleen
AU - Britten, Audrey
AU - Kräutler, Bernhard
AU - Hammock, Bruce D.
AU - Roth, John R.
PY - 2008/2
Y1 - 2008/2
N2 - Corrinoid (vitamin B12-like) cofactors contain various α-axial ligands, including 5,6-dimethylbenzimidazole (DMB) or adenine. The bacterium Salmonella enterica produces the corrin ring only under anaerobic conditions, but it can form "complete" corrinoids aerobically by importing an "incomplete" corrinoid, such as cobinamide (Cbi), and adding appropriate α- and β-axial ligands. Under aerobic conditions, S. enterica performs the corrinoid-dependent degradation of ethanolamine if given vitamin B12, but it can make B12 from exogenous Cbi only if DMB is also provided. Mutants isolated for their ability to degrade ethanolamine without added DMB converted Cbi to pseudo-B12 cofactors (having adenine as an α-axial ligand). The mutations cause an increase in the level of free adenine and install adenine (instead of DMB) as an α-ligand. When DMB is provided to these mutants, synthesis of pseudo-B12 cofactors ceases and B12 cofactors are produced, suggesting that DMB regulates production or incorporation of free adenine as an α-ligand. Wild-type cells make pseudo-B12 cofactors during aerobic growth on propanediol plus Cbi and can use pseudo-vitamin B12 for all of their corrinoid-dependent enzymes. Synthesis of coenzyme pseudo-B12 cofactors requires the same enzymes (CobT, CobU, CobS, and CobC) that install DMB in the formation of coenzyme B12. Models are described for the mechanism and control of α-axial ligand installation.
AB - Corrinoid (vitamin B12-like) cofactors contain various α-axial ligands, including 5,6-dimethylbenzimidazole (DMB) or adenine. The bacterium Salmonella enterica produces the corrin ring only under anaerobic conditions, but it can form "complete" corrinoids aerobically by importing an "incomplete" corrinoid, such as cobinamide (Cbi), and adding appropriate α- and β-axial ligands. Under aerobic conditions, S. enterica performs the corrinoid-dependent degradation of ethanolamine if given vitamin B12, but it can make B12 from exogenous Cbi only if DMB is also provided. Mutants isolated for their ability to degrade ethanolamine without added DMB converted Cbi to pseudo-B12 cofactors (having adenine as an α-axial ligand). The mutations cause an increase in the level of free adenine and install adenine (instead of DMB) as an α-ligand. When DMB is provided to these mutants, synthesis of pseudo-B12 cofactors ceases and B12 cofactors are produced, suggesting that DMB regulates production or incorporation of free adenine as an α-ligand. Wild-type cells make pseudo-B12 cofactors during aerobic growth on propanediol plus Cbi and can use pseudo-vitamin B12 for all of their corrinoid-dependent enzymes. Synthesis of coenzyme pseudo-B12 cofactors requires the same enzymes (CobT, CobU, CobS, and CobC) that install DMB in the formation of coenzyme B12. Models are described for the mechanism and control of α-axial ligand installation.
UR - http://www.scopus.com/inward/record.url?scp=38949170703&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38949170703&partnerID=8YFLogxK
U2 - 10.1128/JB.01386-07
DO - 10.1128/JB.01386-07
M3 - Article
C2 - 17981976
AN - SCOPUS:38949170703
VL - 190
SP - 1160
EP - 1171
JO - Journal of Bacteriology
JF - Journal of Bacteriology
SN - 0021-9193
IS - 4
ER -