Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization
Previous work in our laboratory showed that L-sorbose utilization in Candida albicans is subject to a novel form of regulation which involves a reversible increase or decrease in the copy number of chromosome 5. Furthermore, the structural gene SOU1 is required for L-sorbose utilization and encodes...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Published: |
2005
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| Online Access: | http://hdl.handle.net/20.500.11937/17830 |
| _version_ | 1848749571117678592 |
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| author | Greenberg, J. Price, N. Oliver, Richard Sherman, F. Rustchenko, E. |
| author_facet | Greenberg, J. Price, N. Oliver, Richard Sherman, F. Rustchenko, E. |
| author_sort | Greenberg, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Previous work in our laboratory showed that L-sorbose utilization in Candida albicans is subject to a novel form of regulation which involves a reversible increase or decrease in the copy number of chromosome 5. Furthermore, the structural gene SOU1 is required for L-sorbose utilization and encodes a member of the short chain dehydrogenase family. However, the precise function of SOU1 was not known and neither was the pathway for L-sorbose utilization. We have now expressed SOU1 at a high level from a replicative plasmid having a constitutive ADH1 promoter and purified a version of Sou1p tagged with the FLAG epitope at the N-terminus. Sou1FLAGNp has a sorbose reductase activity which utilizes NADPH as a co-factor and converts L-sorbose to D-sorbitol. It can also less efficiently utilize fructose as a substrate with NADPH as a co-factor, converting fructose to mannitol. In agreement with prediction, the purified enzyme has a subunit molecular weight of 31 kDa and a pI of about 4.8. It probably consists of four identical subunits and has a pH optimum of 6.2. The L-sorbose utilization pathway in C. albicans probably converts L-sorbose to fructose-6-phosphate via D-sorbitol as an intermediate. The first step is catalysed by Sou1p. We also found that C. albicans extracts have a D-sorbitol-6-phosphate dehydrogenase activity, not encoded by SOU1, which utilizes NADP as a co-factor. This activity has not been described previously in yeasts and may be involved in the conversion of phosphorylated D-sorbitol to fructose-6-phosphate or glucose-6-phosphate. |
| first_indexed | 2025-11-14T07:23:03Z |
| format | Journal Article |
| id | curtin-20.500.11937-17830 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:23:03Z |
| publishDate | 2005 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-178302017-09-13T15:42:43Z Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization Greenberg, J. Price, N. Oliver, Richard Sherman, F. Rustchenko, E. Previous work in our laboratory showed that L-sorbose utilization in Candida albicans is subject to a novel form of regulation which involves a reversible increase or decrease in the copy number of chromosome 5. Furthermore, the structural gene SOU1 is required for L-sorbose utilization and encodes a member of the short chain dehydrogenase family. However, the precise function of SOU1 was not known and neither was the pathway for L-sorbose utilization. We have now expressed SOU1 at a high level from a replicative plasmid having a constitutive ADH1 promoter and purified a version of Sou1p tagged with the FLAG epitope at the N-terminus. Sou1FLAGNp has a sorbose reductase activity which utilizes NADPH as a co-factor and converts L-sorbose to D-sorbitol. It can also less efficiently utilize fructose as a substrate with NADPH as a co-factor, converting fructose to mannitol. In agreement with prediction, the purified enzyme has a subunit molecular weight of 31 kDa and a pI of about 4.8. It probably consists of four identical subunits and has a pH optimum of 6.2. The L-sorbose utilization pathway in C. albicans probably converts L-sorbose to fructose-6-phosphate via D-sorbitol as an intermediate. The first step is catalysed by Sou1p. We also found that C. albicans extracts have a D-sorbitol-6-phosphate dehydrogenase activity, not encoded by SOU1, which utilizes NADP as a co-factor. This activity has not been described previously in yeasts and may be involved in the conversion of phosphorylated D-sorbitol to fructose-6-phosphate or glucose-6-phosphate. 2005 Journal Article http://hdl.handle.net/20.500.11937/17830 10.1002/yea.1282 restricted |
| spellingShingle | Greenberg, J. Price, N. Oliver, Richard Sherman, F. Rustchenko, E. Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization |
| title | Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization |
| title_full | Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization |
| title_fullStr | Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization |
| title_full_unstemmed | Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization |
| title_short | Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose Utilization |
| title_sort | candida albicans sou1 encodes a sorbose reductase required for l-sorbose utilization |
| url | http://hdl.handle.net/20.500.11937/17830 |