PUT1 (YLR142W) encodes mitochondrial proline dehydrogenase (proline oxidase, EC 1.5.5.2), a FAD-containing enzyme that oxidises L-proline to 1-pyrroline-5-carboxylate and passes electrons to ubiquinone in the respiratory chain. Together with P5C dehydrogenase (Put2) it converts proline to glutamate, allowing proline, and arginine via proline, to be used as a nitrogen source. PUT1 is induced by proline. Its expression is lower during anaerobic growth in respiratory-competent cells, whereas respiratory-deficient cells lose this oxygen regulation and retain high expression. Respiratory-chain coupling of catalytic proline utilization is distinct from this transcriptional regulation. Purified Put1p has a high Km for proline (36 mM) and uses CoQ1 efficiently; the electron-transfer flavoprotein is not required.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0004657 proline dehydrogenase activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PANTHER PTN004447157 (PRODH clade; human PRODH O43272, mouse, fly sluggish-A, Arabidopsis ERD5/ProDH2, bacterial PutB). Reason: Correct; Put1 activity shown directly on purified protein. Supporting Evidence: PMID:20450881 Put1p also exhibited high activity using ubiquinone-1 (CoQ(1)) as an electron acceptor |
| GO:0004657 proline dehydrogenase activity | IDA PMID:20450881 Purification and characterization of Put1p from Saccharomyce... | ACCEPT | Summary: IDA from Wanduragala et al. 2010: recombinant Put1p purified with bound flavin, kinetics with proline and CoQ1. Reason: Direct biochemical demonstration; core MF. Supporting Evidence: PMID:20450881 Put1p also exhibited high activity using ubiquinone-1 (CoQ(1)) as an electron acceptor PMID:20450881 shown to have a UV-visible absorption spectrum that is typical of a bound flavin cofactor |
| GO:0004657 proline dehydrogenase activity | IEA GO_REF:0000120 | ACCEPT | Summary: IEA via ARBA/InterPro IPR015659 and RHEA:23784/EC 1.5.5.2 (quinone-dependent proline dehydrogenase). Reason: Correct; Put1 uses ubiquinone as electron acceptor. Supporting Evidence: file:yeast/PUT1/PUT1-uniprot.txt Reaction=L-proline + a quinone = (S)-1-pyrroline-5-carboxylate + a |
| GO:0004657 proline dehydrogenase activity | IMP PMID:387737 Genetics and physiology of proline utilization in Saccharomy... | ACCEPT | Summary: IMP from Brandriss and Magasanik 1979: put1 mutants lack proline oxidase activity. Reason: Classic genetic evidence. Supporting Evidence: PMID:387737 Mutants in put1 are deficient in proline oxidase |
| GO:0004657 proline dehydrogenase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (SGD_PWY:ARGDEG-YEAST-PWY) assigning EC 1.5.5.2 to Put1. Reason: Correct reaction assignment. Supporting Evidence: PMID:387737 Mutants in put1 are deficient in proline oxidase |
| GO:0004657 proline dehydrogenase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (SGD_PWY:PROUT-PWY) assigning EC 1.5.5.2 to Put1. Reason: Correct reaction assignment. Supporting Evidence: PMID:387737 Mutants in put1 are deficient in proline oxidase |
| GO:0005739 mitochondrion | HDA PMID:14576278 The proteome of Saccharomyces cerevisiae mitochondria. | ACCEPT | Summary: HDA from the Sickmann et al. 2003 mitochondrial proteome. Reason: Consistent with targeted studies. Supporting Evidence: PMID:14576278 The proteins of highly pure yeast mitochondria were separated by several independent methods and analyzed by tandem MS |
| GO:0005739 mitochondrion | HDA PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen... | ACCEPT | Summary: HDA from the Reinders et al. 2006 PROMITO mitochondrial proteome. Reason: Consistent with targeted studies. Supporting Evidence: PMID:16823961 A total of 851 different proteins (PROMITO dataset) were identified |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: IBA (is_active_in mitochondrion) from PANTHER PTN000357758. Reason: Correct; eukaryotic PRODHs are mitochondrial. Supporting Evidence: PMID:3125423 two PUT1-lacZ gene fusions were constructed that produced mitochondrially localized beta-galactosidase in vivo |
| GO:0005739 mitochondrion | IDA PMID:3125423 Proline utilization in Saccharomyces cerevisiae: sequence, r... | ACCEPT | Summary: IDA from Wang and Brandriss 1987: N-terminal import signal; PUT1-lacZ fusions mitochondrially localized. Reason: Direct evidence. Supporting Evidence: PMID:3125423 two PUT1-lacZ gene fusions were constructed that produced mitochondrially localized beta-galactosidase in vivo |
| GO:0005759 mitochondrial matrix | IEA GO_REF:0000044 | ACCEPT | Summary: Matrix localization is a curated UniProt assignment consistent with mitochondrial targeting and the matrix-side proline-catabolic system. Reason: Retain the established curated subcompartment as a core location with an inference caveat: PMID:3125423 directly tests mitochondrial targeting, not a complete membrane-topology map. Quinone reduction does not by itself contradict a matrix-side enzyme or require this location to be marked peripheral. Supporting Evidence: file:yeast/PUT1/PUT1-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion matrix. |
| GO:0005829 cytosol | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways RCA (SGD_PWY:ARGDEG-YEAST-PWY) placing the proline dehydrogenase reaction in the cytosol. Reason: Contradicted by experimental data: Put1 has a mitochondrial presequence, PUT1-lacZ fusions are mitochondrial, it is found in mitochondrial proteomes, and it feeds electrons to ubiquinone. The cytosol compartment is a pathway-level default of the YeastPathways-to-GO-CAM conversion. Supporting Evidence: PMID:3125423 two PUT1-lacZ gene fusions were constructed that produced mitochondrially localized beta-galactosidase in vivo PMID:20450881 The PUT1 gene encodes Put1p, a proline dehydrogenase (PRODH) enzyme localized in the mitochondrion |
| GO:0005829 cytosol | RCA GO_REF:0000123 | REMOVE | Summary: YeastPathways RCA (SGD_PWY:PROUT-PWY) placing the proline dehydrogenase reaction in the cytosol. Reason: Contradicted by experimental data: Put1 has a mitochondrial presequence, PUT1-lacZ fusions are mitochondrial, it is found in mitochondrial proteomes, and it feeds electrons to ubiquinone. The cytosol compartment is a pathway-level default of the YeastPathways-to-GO-CAM conversion. Supporting Evidence: PMID:3125423 two PUT1-lacZ gene fusions were constructed that produced mitochondrially localized beta-galactosidase in vivo PMID:20450881 The PUT1 gene encodes Put1p, a proline dehydrogenase (PRODH) enzyme localized in the mitochondrion |
| GO:0006527 L-arginine catabolic process | RCA GO_REF:0000123 | KEEP AS NON CORE | Summary: YeastPathways RCA (SGD_PWY:ARGDEG-YEAST-PWY, arginine degradation) placing Put1 in L-arginine catabolism. Reason: In yeast, arginine-derived P5C is converted to proline and then oxidised by Put1/Put2, so Put1 does catalyse a step of the arginine-to-glutamate route; secondary to its proline-degradation role. Supporting Evidence: PMID:387737 The arginine-degradative pathway intersects the proline-degradative pathway at P5C PMID:6997271 Proline was then converted back to P5C and finally to glutamate by the Put enzymes proline oxidase and P5C dehydrogenase. |
| GO:0006562 L-proline catabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PANTHER PTN004447157 for L-proline catabolic process. Reason: Correct. Supporting Evidence: PMID:387737 Mutants in put1 are deficient in proline oxidase |
| GO:0006562 L-proline catabolic process | IDA PMID:20450881 Purification and characterization of Put1p from Saccharomyce... | ACCEPT | Summary: IDA (PMID:20450881) for L-proline catabolic process. Reason: Put1 catalyses the first step of proline degradation to glutamate; put1 mutants cannot use proline as nitrogen source. Supporting Evidence: PMID:20450881 The PUT1 gene encodes Put1p, a proline dehydrogenase (PRODH) enzyme localized in the mitochondrion |
| GO:0006562 L-proline catabolic process | IEA GO_REF:0000002 | ACCEPT | Summary: IEA from InterPro IPR015659 (proline oxidase family). Reason: Correct. Supporting Evidence: file:yeast/PUT1/PUT1-uniprot.txt PATHWAY: Amino-acid degradation; L-proline degradation into L- |
| GO:0006562 L-proline catabolic process | IMP PMID:387737 Genetics and physiology of proline utilization in Saccharomy... | ACCEPT | Summary: IMP (PMID:387737) for L-proline catabolic process. Reason: Put1 catalyses the first step of proline degradation to glutamate; put1 mutants cannot use proline as nitrogen source. Supporting Evidence: PMID:387737 Mutants in put1 are deficient in proline oxidase |
| GO:0006562 L-proline catabolic process | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways RCA (PROUT-PWY, L-proline degradation). Reason: Correct. Supporting Evidence: PMID:387737 Mutants in put1 are deficient in proline oxidase |
| GO:0071949 FAD binding | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PANTHER PTN000357758 (seeded by human PRODH O43272) for FAD binding. Reason: Purified Put1p carries a bound flavin; FAD is the catalytic cofactor of the PRODH (betaalpha)8 barrel. Supporting Evidence: PMID:20450881 shown to have a UV-visible absorption spectrum that is typical of a bound flavin cofactor |
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Download this section (compressed HTML)Q: Is Put1 a peripheral inner-membrane protein (matrix face) as expected for a quinone-reducing PRODH, or a soluble matrix protein as UniProt states?
Experiment: Submitochondrial fractionation (carbonate extraction, protease protection) of tagged Put1.
Proline oxidase; nuclear-encoded mitochondrial protein involved in utilization of proline as sole nitrogen source; PUT1 transcription is induced by Put3p in the presence of proline and the absence of a preferred nitrogen source
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